diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
new file mode 100644
index 0000000..7643783
--- /dev/null
+++ b/.idea/codeStyles/Project.xml
@@ -0,0 +1,123 @@
+<component name="ProjectCodeStyleConfiguration">
+  <code_scheme name="Project" version="173">
+    <JetCodeStyleSettings>
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </JetCodeStyleSettings>
+    <codeStyleSettings language="XML">
+      <option name="FORCE_REARRANGE_MODE" value="1" />
+      <indentOptions>
+        <option name="CONTINUATION_INDENT_SIZE" value="4" />
+      </indentOptions>
+      <arrangement>
+        <rules>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>xmlns:android</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>xmlns:.*</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:id</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:name</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>name</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>style</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>ANDROID_ATTRIBUTE_ORDER</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>.*</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+        </rules>
+      </arrangement>
+    </codeStyleSettings>
+    <codeStyleSettings language="kotlin">
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </codeStyleSettings>
+  </code_scheme>
+</component>
\ No newline at end of file
diff --git a/.idea/codeStyles/codeStyleConfig.xml b/.idea/codeStyles/codeStyleConfig.xml
new file mode 100644
index 0000000..79ee123
--- /dev/null
+++ b/.idea/codeStyles/codeStyleConfig.xml
@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
+  </state>
+</component>
\ No newline at end of file
diff --git a/app/src/main/java/meow/sweetbread/lincalc/MainActivity.kt b/app/src/main/java/meow/sweetbread/lincalc/MainActivity.kt
index c3af147..d6bda8a 100644
--- a/app/src/main/java/meow/sweetbread/lincalc/MainActivity.kt
+++ b/app/src/main/java/meow/sweetbread/lincalc/MainActivity.kt
@@ -3,6 +3,7 @@ package meow.sweetbread.lincalc
 import android.annotation.SuppressLint
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import android.os.LimitExceededException
 import android.util.Log
 import android.widget.Button
 import android.widget.ImageButton
@@ -27,12 +28,14 @@ class MainActivity : AppCompatActivity() {
         priority["*"] = 2
         priority["/"] = 2
         priority["^"] = 3
+        priority["√"] = 3
 
         tokensType["+"] = Tokens.Operations
         tokensType["-"] = Tokens.Operations
         tokensType["*"] = Tokens.Operations
         tokensType["/"] = Tokens.Operations
         tokensType["^"] = Tokens.Operations
+        tokensType["√"] = Tokens.Function
         tokensType["+"] = Tokens.Operations
         tokensType["+"] = Tokens.Operations
         tokensType["("] = Tokens.BracketOpen
@@ -63,7 +66,7 @@ class MainActivity : AppCompatActivity() {
         findViewById<Button>(R.id.btn_sqrt).setOnClickListener { btn_listener(it as Button) }
 
         findViewById<Button>(R.id.btn_pi).setOnClickListener { btn_listener(it as Button) }
-        findViewById<Button>(R.id.btn_elr).setOnClickListener { btn_listener(it as Button) }
+//        findViewById<Button>(R.id.btn_elr).setOnClickListener { btn_listener(it as Button) }
 
         findViewById<Button>(R.id.btn_x).setOnClickListener { btn_listener(it as Button) }
 
@@ -71,61 +74,68 @@ class MainActivity : AppCompatActivity() {
 
         val image = findViewById<TextView>(R.id.input)
 
-        findViewById<ImageButton>(R.id.del).setOnClickListener {
+        findViewById<Button>(R.id.btn_del).setOnClickListener {
             image.text = image.text.dropLast(1)
         }
 
         findViewById<Button>(R.id.btn_sbm).setOnClickListener {
-            findViewById<TextView>(R.id.last_exp_out).text = findViewById<TextView>(R.id.input).text.toString()
-            val equations = findViewById<TextView>(R.id.input).text.toString().split('=')
-            if (equations.size == 1) {
-                val answer = evaluate(toRpn(tokenizer(equations[0])))
-                val value = if (answer.value.toString().split('.')[1] == "0")
-                    (answer.value as Double).toInt().toString()
-                else (answer.value as Double).toFloat().toString()
-                findViewById<TextView>(R.id.left_out).text = answer.toString()
+            try {
                 findViewById<TextView>(R.id.last_exp_out).text =
-                    findViewById<TextView>(R.id.last_exp_out).text.toString() + " = " + value
-                findViewById<TextView>(R.id.input).text = ""
-            } else {
-                var left = evaluate(toRpn(tokenizer(equations[0])))
-                var right = evaluate(toRpn(tokenizer(equations[1])))
-
-                if (((left.type == Tokens.Number) and (right.type != Tokens.Number)) or
-                    (left.type == Tokens.Linear) and (right.type == Tokens.Quadratic)) {
-                    val tmp = right
-                    left = right
-                    right = tmp
-                }
-
-                findViewById<TextView>(R.id.left_out).text = left.toString()
-                findViewById<TextView>(R.id.right_out).text = right.toString()
-
-                if (left.type == Tokens.Number) {
-                    val value = if (left.value.toString().split('.')[1] == "0")
-                        (left.value as Double).toInt().toString()
-                    else left.value.toString()
+                    findViewById<TextView>(R.id.input).text.toString()
+                val equations = findViewById<TextView>(R.id.input).text.toString().split('=')
+                if (equations.size == 1) {
+                    val answer = evaluate(toRpn(tokenizer(equations[0])))
+                    val value = if (answer.value.toString().split('.')[1] == "0")
+                        (answer.value as Double).toInt().toString()
+                    else (answer.value as Double).toFloat().toString()
+                    findViewById<TextView>(R.id.left_out).text = answer.toString()
                     findViewById<TextView>(R.id.last_exp_out).text =
                         findViewById<TextView>(R.id.last_exp_out).text.toString() + " = " + value
                     findViewById<TextView>(R.id.input).text = ""
-                } else if (left.type == Tokens.Linear) {
-                    val answer: Double
-
-                    answer = if (right.type == Tokens.Number)
-                        (left.value as Linear - right.value as Double).answer()
-                    else
-                        (left.value as Linear - right.value as Linear).answer()
-                    val value: String
-                    value = if (answer.toString().split('.')[1] == "0")
-                        answer.toInt().toString()
-                    else answer.toString()
-                    findViewById<TextView>(R.id.last_exp_out).text =
-                        findViewById<TextView>(R.id.last_exp_out).text.toString() +
-                                "\n${(left.value as Linear).name} = " + value
-                    findViewById<TextView>(R.id.input).text = ""
                 } else {
+                    var left = evaluate(toRpn(tokenizer(equations[0])))
+                    var right = evaluate(toRpn(tokenizer(equations[1])))
 
+                    if (((left.type == Tokens.Number) and (right.type != Tokens.Number)) or
+                        (left.type == Tokens.Linear) and (right.type == Tokens.Quadratic)
+                    ) {
+                        val tmp = right
+                        left = right
+                        right = tmp
+                    }
+
+                    findViewById<TextView>(R.id.left_out).text = left.toString()
+                    findViewById<TextView>(R.id.right_out).text = right.toString()
+
+                    if (left.type == Tokens.Number) {
+                        val value = if (left.value.toString().split('.')[1] == "0")
+                            (left.value as Double).toInt().toString()
+                        else left.value.toString()
+                        findViewById<TextView>(R.id.last_exp_out).text =
+                            findViewById<TextView>(R.id.last_exp_out).text.toString() + " = " + value
+                        findViewById<TextView>(R.id.input).text = ""
+                    } else if (left.type == Tokens.Linear) {
+                        val answer: Double
+
+                        answer = if (right.type == Tokens.Number)
+                            (left.value as Linear - right.value as Double).answer()
+                        else
+                            (left.value as Linear - right.value as Linear).answer()
+                        val value: String
+                        value = if (answer.toFloat().toString().split('.')[1] == "0")
+                            answer.toInt().toString()
+                        else answer.toString()
+                        findViewById<TextView>(R.id.last_exp_out).text =
+                            findViewById<TextView>(R.id.last_exp_out).text.toString() +
+                                    "\n${(left.value as Linear).name} = " + value
+                        findViewById<TextView>(R.id.input).text = ""
+                    } else {
+
+                    }
                 }
+            } catch (e: java.lang.Exception) {
+                findViewById<TextView>(R.id.last_exp_out).text = "Ошибка"
+                findViewById<TextView>(R.id.right_out).text = e.stackTraceToString()
             }
         }
     }
@@ -149,21 +159,37 @@ class MainActivity : AppCompatActivity() {
                     pos++
                 }
                 if (tokens.isNotEmpty()) {
-                    if (tokens.last().type in arrayOf(Tokens.BracketClose, Tokens.Constant, Tokens.Variable))
+                    if (tokens.last().type in arrayOf(
+                            Tokens.BracketClose,
+                            Tokens.Constant,
+                            Tokens.Variable
+                        )
+                    )
                         tokens += Token(Tokens.Operations, "*")
                 }
                 tokens += Token(Tokens.Number, exp.substring(position, pos).toDouble())
                 position = pos
             } else if (chr == 'X') {
                 if (tokens.isNotEmpty()) {
-                    if (tokens.last().type in arrayOf(Tokens.BracketClose, Tokens.Constant, Tokens.Number))
+                    if (tokens.last().type in arrayOf(
+                            Tokens.BracketClose,
+                            Tokens.Constant,
+                            Tokens.Number
+                        )
+                    )
                         tokens += Token(Tokens.Operations, "*")
                 }
                 tokens += Token(Tokens.Variable, chr.toString())
                 position++
-            } else if (chr.toString() in constants.keys){
+            } else if (chr.toString() in constants.keys) {
                 if (tokens.isNotEmpty()) {
-                    if (tokens.last().type in arrayOf(Tokens.BracketClose, Tokens.Constant, Tokens.Variable, Tokens.Number))
+                    if (tokens.last().type in arrayOf(
+                            Tokens.BracketClose,
+                            Tokens.Constant,
+                            Tokens.Variable,
+                            Tokens.Number
+                        )
+                    )
                         tokens += Token(Tokens.Operations, "*")
                 }
                 tokens += Token(Tokens.Constant, chr.toString())
@@ -176,21 +202,26 @@ class MainActivity : AppCompatActivity() {
                     pos++
                 }
                 if (tokens.isNotEmpty()) {
-                    if (tokens.last().type in arrayOf(Tokens.BracketClose, Tokens.Constant, Tokens.Variable))
+                    if (tokens.last().type in arrayOf(
+                            Tokens.BracketClose,
+                            Tokens.Constant,
+                            Tokens.Variable
+                        )
+                    )
                         tokens += Token(Tokens.Operations, "*")
                 }
                 tokens += Token(Tokens.Function, exp.substring(position, pos))
                 position = pos
-            }
-            else if (tokensType.containsKey(chr.toString())) {
+            } else if (tokensType.containsKey(chr.toString())) {
                 if (tokens.isNotEmpty()) {
                     if ((tokensType[chr.toString()]!! == Tokens.BracketOpen) and
-                        (tokens.last().type in arrayOf(Tokens.Number, Tokens.Variable)))
+                        (tokens.last().type in arrayOf(Tokens.Number, Tokens.Variable))
+                    )
                         tokens += Token(Tokens.Operations, "*")
-                    if ((chr == '-') and (tokens.last().type != Tokens.Number))
-                        tokens += Token(Tokens.Number, 0.toDouble())
-                } else if (chr == '-')
-                    tokens += Token(Tokens.Number, 0.toDouble())
+//                    if ((chr == '-') and (tokens.last().type != Tokens.Number))
+//                        tokens += Token(Tokens.Number, 0.0)
+                } // else if (chr == '-')
+//                    tokens += Token(Tokens.Number, 0.0)
                 tokens += Token(tokensType[chr.toString()]!!, chr.toString())
                 position++
             } else {
@@ -232,7 +263,8 @@ class MainActivity : AppCompatActivity() {
                     while (
                         (priority[token.value]!! < priority[act_buf.last().value]!!) or
                         ((priority[token.value]!! == priority[act_buf.last().value]!!) and
-                                (token.value in leftAssociative))) {
+                                (token.value in leftAssociative))
+                    ) {
                         out_buf += act_buf.removeLast()
                         if (act_buf.isEmpty())
                             break
@@ -241,7 +273,7 @@ class MainActivity : AppCompatActivity() {
                 act_buf += token
             } else if (token.type == Tokens.BracketOpen)
                 act_buf += token
-            else if (token.type == Tokens.BracketClose){
+            else if (token.type == Tokens.BracketClose) {
                 while (act_buf.last().type != Tokens.BracketOpen)
                     out_buf += act_buf.removeLast()
                 act_buf.removeLast()
@@ -268,62 +300,181 @@ class MainActivity : AppCompatActivity() {
         var tmp_buf = listOf<Token>()
 
         while (buffer.size != 1) {
-            val token = buffer[position]
+            var token = buffer[position]
 
             if (token.type == Tokens.Function) {
-                if (token.value == "sqrt") {
+                if (token.value == "√") {
                     tmp_buf = buffer.dropLast(ext.size - position + 1)
                     var res = Token(Tokens.Number, sqrt(buffer[position - 1].value as Double))
                     tmp_buf += res
-                    tmp_buf += buffer.drop(position+1)
+                    tmp_buf += buffer.drop(position + 1)
                 }
             } else if (token.type == Tokens.Operations) {
-                val first = buffer[position-2]
-                val second = buffer[position-1]
+                val first = buffer[position - 2].value
+                val second = buffer[position - 1].value
 
                 //TODO: make operations with other objects
-                if (token.value == "+") {
-                    tmp_buf = buffer.dropLast(ext.size - position + 2)
-                    var res: Token
-                    if ((first.type == Tokens.Number) and (second.type == Tokens.Number))
-                        res = Token(Tokens.Number, (first.value as Double + second.value  as Double))
-                    else if ((first.type == Tokens.Variable) and (second.type == Tokens.Number))
-                        res = Token(Tokens.Linear, Linear(first.value as String, second.value as Double, 0.toDouble()))
-                    else
-                        res = Token(Tokens.Linear, Linear(second.value as String, first.value as Double, 0.toDouble()))
-                    tmp_buf += res
-                    tmp_buf += buffer.drop(position+1)
-                } else if (token.value == "-") {
-                    tmp_buf = buffer.dropLast(ext.size - position + 2)
-                    val res = Token(Tokens.Number, (first.value as Double - second.value as Double))
-                    tmp_buf += res
-                    tmp_buf += buffer.drop(position+1)
-                } else if (token.value == "*") {
-                    tmp_buf = buffer.dropLast(ext.size - position + 2)
-                    val res: Token
-                    res = if ((first.type == Tokens.Number) and (second.type == Tokens.Number))
-                        Token(Tokens.Number, first.value as Double*second.value as Double)
-                    else if ((first.type == Tokens.Number) and (second.type == Tokens.Variable))
-                        Token(Tokens.Linear, Linear(second.value as String, 0.toDouble(), first.value as Double))
-                    else if ((first.type == Tokens.Variable) and (second.type == Tokens.Number))
-                        Token(Tokens.Linear, Linear(first.value as String, 0.toDouble(), second.value as Double))
-                    else //if ((first.type == Tokens.Variable) and (second.type == Tokens.Variable))
-                        Token(Tokens.Quadratic, Quadratic(first.value as String, 0.toDouble(), 0.toDouble(), 2.toDouble()))
-                    tmp_buf += res
-                    tmp_buf += buffer.drop(position+1)
-                } else if (token.value == "/") {
-                    tmp_buf = buffer.dropLast(ext.size - position + 2)
-                    val res = Token(Tokens.Number, first.value as Double/second.value as Double)
-                    tmp_buf += res
-                    tmp_buf += buffer.drop(position+1)
-                } else if (token.value == "^") {
-                    tmp_buf = buffer.dropLast(ext.size - position + 2)
-                    val res = Token(
-                        Tokens.Number, (first.value as Double)
-                            .pow(second.value as Double)
-                    )
-                    tmp_buf += res
-                    tmp_buf += buffer.drop(position + 1)
+                when (token.value) {
+                    "+" -> {
+                        tmp_buf = buffer.dropLast(ext.size - position + 2)
+                        val res: Token =
+                            if ((first is Double) and (second is Double))
+                                Token(
+                                    Tokens.Number,
+                                    (first as Double + second as Double)
+                                )
+                            else if ((first is String) and (second is Double))
+                                Token(
+                                    Tokens.Linear,
+                                    Linear(first as String, second as Double, 0.0)
+                                )
+                            else if ((first is Linear) and (second is Double))
+                                Token(
+                                    Tokens.Linear, Linear(
+                                        (first as Linear).name,
+                                        (first as Linear).add + (second as Double),
+                                        (first as Linear).mul
+                                    )
+                                )
+                            else
+                                Token(
+                                    Tokens.Linear,
+                                    Linear(second as String, first as Double, 0.0)
+                                )
+                        tmp_buf += res
+                        tmp_buf += buffer.drop(position + 1)
+                    }
+                    "-" -> {
+                        tmp_buf = buffer.dropLast(ext.size - position + 2)
+                        val res: Token = when (first) {
+                            is Double -> {
+                                when (second) {
+                                    is Double -> {
+                                        Token(Tokens.Number, (first - second))
+                                    }
+                                    is String -> {
+                                        Token(Tokens.Linear, Linear(second, first, -1.0))
+                                    }
+                                    is Linear -> {
+                                        Token(
+                                            Tokens.Linear,
+                                            Linear(
+                                                second.name,
+                                                first - second.add,
+                                                -1.0 * second.mul
+                                            )
+                                        )
+                                    }
+                                    else -> {
+                                        Token(Tokens.Linear, "")
+                                    }
+                                }
+                            }
+                            is String -> {
+                                when (second) {
+                                    is Double -> {
+                                        Token(Tokens.Linear, Linear(first, -second, 1.0))
+                                    }
+                                    is String -> {
+                                        Token(Tokens.Quadratic, Quadratic(first, 0.0, 1.0, 2.0))
+                                    }
+                                    else -> {
+                                        Token(Tokens.Linear, "")
+                                    }
+                                }
+                            }
+                            is Linear -> {
+                                when (second) {
+                                    is Double -> {
+                                        Token(
+                                            Tokens.Linear,
+                                            Linear(first.name, first.add - second, first.mul)
+                                        )
+                                    }
+                                    else -> {
+                                        Token(Tokens.Linear, "")
+                                    }
+                                }
+                            }
+
+                            else -> {
+                                Token(Tokens.Linear, "")
+                            }
+                        }
+                        tmp_buf += res
+                        tmp_buf += buffer.drop(position + 1)
+                    }
+                    "*" -> {
+                        tmp_buf = buffer.dropLast(ext.size - position + 2)
+
+                        val res: Token = when (first) {
+                            is Double -> {
+                                when (second) {
+                                    is Double -> {
+                                        Token(Tokens.Number, first * second)
+                                    }
+                                    is String -> {
+                                        Token(Tokens.Linear, Linear(second, 0.0, first))
+                                    }
+                                    is Linear -> {
+                                        Token(Tokens.Linear, second * first)
+                                    }
+                                    else -> {
+                                        Token(Tokens.Linear, "")
+                                    }
+                                }
+                            }
+                            is String -> {
+                                when (second) {
+                                    is Double -> {
+                                        Token(Tokens.Linear, Linear(first, 0.0, second))
+                                    }
+                                    is String -> {
+                                        Token(Tokens.Quadratic, "")
+                                    }
+                                    is Linear -> {
+                                        Token(Tokens.Quadratic, "")
+                                    }
+                                    else -> {
+                                        Token(Tokens.Quadratic, "")
+                                    }
+                                }
+                            }
+                            else -> {
+                                Token(Tokens.Quadratic, "")
+                            }
+                        }
+                        tmp_buf += res
+                        tmp_buf += buffer.drop(position + 1)
+                    }
+                    "/" -> {
+                        tmp_buf = buffer.dropLast(ext.size - position + 2)
+                        val res: Token =
+                            if ((first is Double) and (second is Double))
+                                Token(Tokens.Number, first as Double / second as Double)
+                            else if ((first is String) and (second is Double))
+                                Token(
+                                    Tokens.Linear,
+                                    Linear(
+                                        first as String,
+                                        0.0,
+                                        1.0 / (second as Double)
+                                    )
+                                )
+                            else
+                                Token(Tokens.Number, 0.0)
+                        tmp_buf += res
+                        tmp_buf += buffer.drop(position + 1)
+                    }
+                    "^" -> {
+                        tmp_buf = buffer.dropLast(ext.size - position + 2)
+                        val res = Token(
+                            Tokens.Number, (first as Double)
+                                .pow(second as Double)
+                        )
+                        tmp_buf += res
+                        tmp_buf += buffer.drop(position + 1)
+                    }
                 }
             } else {
                 position++
@@ -352,7 +503,7 @@ enum class Tokens {
     Quadratic
 }
 
-class Token (val type: Tokens, var value: Any) {
+class Token(val type: Tokens, val value: Any) {
     override fun toString(): String {
         return "<$type, $value>"
     }
@@ -364,22 +515,26 @@ open class MathObject(val value: Any) {
     }
 }
 
-class Linear(val name: String, private val add: Double, private val mul: Double) : MathObject("$mul*$name+$add") {
+class Linear(val name: String, val add: Double, val mul: Double) : MathObject("$mul*$name+$add") {
     //TODO: Implement more methods
     override fun toString(): String {
         return "$mul*$name+$add"
     }
 
     operator fun minus(num: Double): Linear {
-        return Linear(name, add-num, mul)
+        return Linear(name, add - num, mul)
     }
 
     operator fun minus(lin: Linear): Linear {
 //        if (name != lin.name) throw IllegalArgumentException
-        return Linear(name, add-lin.add, mul-lin.mul)
+        return Linear(name, add - lin.add, mul - lin.mul)
     }
 
-    fun answer() = -add/mul
+    operator fun times(num: Double): Linear {
+        return Linear(name, add, mul * num)
+    }
+
+    fun answer() = -add / mul
 }
 
 class Quadratic(name: String, add: Double, mul: Double, pow: Double) {
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 094bb09..3837959 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -21,12 +21,21 @@
 
     <TextView
         android:id="@+id/input"
-        android:layout_width="0dp"
+        android:layout_width="wrap_content"
         android:layout_height="100dp"
         android:layout_marginTop="24dp"
+        android:textSize="60sp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <TextView
+        android:id="@+id/last_exp_out"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:textSize="24sp"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        app:layout_constraintTop_toBottomOf="@+id/input" />
 
     <TextView
         android:id="@+id/RPN_out"
@@ -49,386 +58,443 @@
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintTop_toBottomOf="@+id/left_out" />
 
-    <TextView
-        android:id="@+id/last_exp_out"
-        android:layout_width="0dp"
+    <Space
+        android:id="@+id/space"
+        android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/input" />
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_bias="0.55" />
 
     <LinearLayout
-        android:id="@+id/linearLayout2"
         android:layout_width="0dp"
-        android:layout_height="wrap_content"
-        android:orientation="horizontal"
-        app:layout_constraintBottom_toTopOf="@+id/linearLayout"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent">
-
-        <Button
-            android:id="@+id/button25"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:layout_weight="1"
-            android:backgroundTint="#80323232"
-            android:backgroundTintMode="src_in"
-            android:hapticFeedbackEnabled="false"
-            android:insetTop="0dp"
-            android:insetBottom="0dp"
-            android:text="+"
-            app:cornerRadius="0dp" />
-
-        <Button
-            android:id="@+id/button22"
-            android:layout_width="wrap_content"
-            android:layout_height="match_parent"
-            android:layout_weight="1"
-            android:backgroundTint="#80323232"
-            android:backgroundTintMode="src_in"
-            android:hapticFeedbackEnabled="false"
-            android:insetTop="0dp"
-            android:insetBottom="0dp"
-            android:text="-"
-            app:cornerRadius="0dp" />
-
-        <Button
-            android:id="@+id/button24"
-            android:layout_width="wrap_content"
-            android:layout_height="match_parent"
-            android:layout_weight="1"
-            android:backgroundTint="#80323232"
-            android:backgroundTintMode="src_in"
-            android:hapticFeedbackEnabled="false"
-            android:insetTop="0dp"
-            android:insetBottom="0dp"
-            android:text="*"
-            app:cornerRadius="0dp" />
-
-        <Button
-            android:id="@+id/button23"
-            android:layout_width="wrap_content"
-            android:layout_height="match_parent"
-            android:layout_weight="1"
-            android:backgroundTint="#80323232"
-            android:backgroundTintMode="src_in"
-            android:hapticFeedbackEnabled="false"
-            android:insetTop="0dp"
-            android:insetBottom="0dp"
-            android:text="/"
-            app:cornerRadius="0dp" />
-    </LinearLayout>
-
-    <LinearLayout
-        android:id="@+id/linearLayout"
-        android:layout_width="0dp"
-        android:layout_height="wrap_content"
-        android:orientation="horizontal"
+        android:layout_height="0dp"
+        android:orientation="vertical"
         app:layout_constraintBottom_toBottomOf="@+id/imageView2"
         app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent">
-
-        <TableLayout
-            android:id="@+id/tableLayout2"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:layout_weight="3">
-
-            <TableRow
-                android:layout_width="match_parent"
-                android:layout_height="match_parent">
-
-                <Button
-                    android:id="@+id/button13"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="1"
-                    app:cornerRadius="0dp" />
-
-                <Button
-                    android:id="@+id/button12"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="2"
-                    app:cornerRadius="0dp" />
-
-                <Button
-                    android:id="@+id/button"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="3"
-                    app:cornerRadius="0dp" />
-
-            </TableRow>
-
-            <TableRow
-                android:layout_width="match_parent"
-                android:layout_height="match_parent">
-
-                <Button
-                    android:id="@+id/button5"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="4"
-                    app:cornerRadius="0dp" />
-
-                <Button
-                    android:id="@+id/button15"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="5"
-                    app:cornerRadius="0dp" />
-
-                <Button
-                    android:id="@+id/button14"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="6"
-                    app:cornerRadius="0dp" />
-
-            </TableRow>
-
-            <TableRow
-                android:layout_width="match_parent"
-                android:layout_height="match_parent">
-
-                <Button
-                    android:id="@+id/button6"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="7"
-                    app:cornerRadius="0dp" />
-
-                <Button
-                    android:id="@+id/button16"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="8"
-                    app:cornerRadius="0dp" />
-
-                <Button
-                    android:id="@+id/button10"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="9"
-                    app:cornerRadius="0dp" />
-            </TableRow>
-
-            <TableRow
-                android:layout_width="match_parent"
-                android:layout_height="match_parent">
-
-                <Button
-                    android:id="@+id/button17"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="0"
-                    app:cornerRadius="0dp" />
-
-                <Button
-                    android:id="@+id/button11"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text="("
-                    app:cornerRadius="0dp" />
-
-                <Button
-                    android:id="@+id/button7"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:backgroundTint="#80141414"
-                    android:backgroundTintMode="src_in"
-                    android:hapticFeedbackEnabled="false"
-                    android:insetTop="0dp"
-                    android:insetBottom="0dp"
-                    android:text=")"
-                    app:cornerRadius="0dp" />
-            </TableRow>
-        </TableLayout>
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/space">
 
         <LinearLayout
-            android:layout_width="wrap_content"
-            android:layout_height="match_parent"
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
             android:layout_weight="1"
+            android:backgroundTint="#4D333333"
             android:orientation="vertical">
 
             <Button
-                android:id="@+id/button21"
+                android:id="@+id/btn_sbm"
                 android:layout_width="match_parent"
-                android:layout_height="wrap_content"
+                android:layout_height="match_parent"
+                android:backgroundTint="#80505050"
+                android:backgroundTintMode="src_in"
+                android:hapticFeedbackEnabled="false"
+                android:insetTop="0dp"
+                android:insetBottom="0dp"
+                android:text="Вычислить"
+                android:textSize="20sp"
+                app:cornerRadius="0dp" />
+        </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/linearLayout3"
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1"
+            android:orientation="horizontal">
+
+            <Button
+                android:id="@+id/btn_x"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
+                android:backgroundTint="#80505050"
+                android:backgroundTintMode="src_in"
+                android:hapticFeedbackEnabled="false"
+                android:insetTop="0dp"
+                android:insetBottom="0dp"
+                android:text="X"
+                android:textSize="24sp"
+                app:cornerRadius="0dp" />
+
+            <Button
+                android:id="@+id/btn_equ"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
+                android:backgroundTint="#80505050"
+                android:backgroundTintMode="src_in"
+                android:hapticFeedbackEnabled="false"
+                android:insetTop="0dp"
+                android:insetBottom="0dp"
+                android:text="="
+                android:textSize="24sp"
+                app:cornerRadius="0dp" />
+
+            <Button
+                android:id="@+id/btn_pi"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
+                android:backgroundTint="#80505050"
+                android:backgroundTintMode="src_in"
+                android:insetTop="0dp"
+                android:insetBottom="0dp"
+                android:text="π"
+                android:textAllCaps="false"
+                android:textSize="24sp"
+                app:cornerRadius="0dp" />
+
+            <Button
+                android:id="@+id/btn_dot"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
+                android:backgroundTint="#80505050"
+                android:insetTop="0dp"
+                android:insetBottom="0dp"
+                android:text="."
+                android:textSize="24sp"
+                app:cornerRadius="0dp" />
+        </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/linearLayout2"
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1"
+            android:orientation="horizontal">
+
+            <Button
+                android:id="@+id/btn_add"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
                 android:backgroundTint="#80323232"
                 android:backgroundTintMode="src_in"
                 android:hapticFeedbackEnabled="false"
                 android:insetTop="0dp"
                 android:insetBottom="0dp"
-                android:text="^"
+                android:text="+"
+                android:textSize="24sp"
                 app:cornerRadius="0dp" />
 
             <Button
-                android:id="@+id/button19"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
+                android:id="@+id/btn_sub"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
                 android:backgroundTint="#80323232"
                 android:backgroundTintMode="src_in"
                 android:hapticFeedbackEnabled="false"
                 android:insetTop="0dp"
                 android:insetBottom="0dp"
-                android:text="sqrt"
+                android:text="-"
+                android:textSize="24sp"
                 app:cornerRadius="0dp" />
 
             <Button
-                android:id="@+id/button20"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                android:layout_weight="2"
-                android:backgroundTint="#803A2121"
+                android:id="@+id/btn_mul"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
+                android:backgroundTint="#80323232"
                 android:backgroundTintMode="src_in"
                 android:hapticFeedbackEnabled="false"
                 android:insetTop="0dp"
                 android:insetBottom="0dp"
-                app:cornerRadius="0dp"
-                app:icon="@android:drawable/ic_input_delete"
-                app:iconGravity="textStart"
-                app:iconPadding="0dp" />
+                android:text="*"
+                android:textSize="24sp"
+                app:cornerRadius="0dp" />
 
+            <Button
+                android:id="@+id/btn_div"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
+                android:backgroundTint="#80323232"
+                android:backgroundTintMode="src_in"
+                android:hapticFeedbackEnabled="false"
+                android:insetTop="0dp"
+                android:insetBottom="0dp"
+                android:text="/"
+                android:textSize="24sp"
+                app:cornerRadius="0dp" />
+        </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/linearLayout"
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="4"
+            android:orientation="horizontal">
+
+            <TableLayout
+                android:id="@+id/tableLayout2"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="3">
+
+                <TableRow
+                    android:layout_width="match_parent"
+                    android:layout_height="0dp"
+                    android:layout_weight="1">
+
+                    <Button
+                        android:id="@+id/btn_1"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="1"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                    <Button
+                        android:id="@+id/btn_2"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="2"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                    <Button
+                        android:id="@+id/btn_3"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="3"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                </TableRow>
+
+                <TableRow
+                    android:layout_width="match_parent"
+                    android:layout_height="0dp"
+                    android:layout_weight="1">
+
+                    <Button
+                        android:id="@+id/btn_4"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="4"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                    <Button
+                        android:id="@+id/btn_5"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="5"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                    <Button
+                        android:id="@+id/btn_6"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="6"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                </TableRow>
+
+                <TableRow
+                    android:layout_width="match_parent"
+                    android:layout_height="0dp"
+                    android:layout_weight="1">
+
+                    <Button
+                        android:id="@+id/btn_7"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="7"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                    <Button
+                        android:id="@+id/btn_8"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="8"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                    <Button
+                        android:id="@+id/btn_9"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="9"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+                </TableRow>
+
+                <TableRow
+                    android:layout_width="match_parent"
+                    android:layout_height="0dp"
+                    android:layout_weight="1">
+
+                    <Button
+                        android:id="@+id/btn_0"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="0"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                    <Button
+                        android:id="@+id/btn_bro"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text="("
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+
+                    <Button
+                        android:id="@+id/btn_brc"
+                        android:layout_width="wrap_content"
+                        android:layout_height="match_parent"
+                        android:layout_weight="1"
+                        android:backgroundTint="#80141414"
+                        android:backgroundTintMode="src_in"
+                        android:hapticFeedbackEnabled="false"
+                        android:insetTop="0dp"
+                        android:insetBottom="0dp"
+                        android:text=")"
+                        android:textSize="24sp"
+                        app:cornerRadius="0dp" />
+                </TableRow>
+            </TableLayout>
+
+            <LinearLayout
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
+                android:orientation="vertical">
+
+                <Button
+                    android:id="@+id/btn_pow"
+                    android:layout_width="match_parent"
+                    android:layout_height="0dp"
+                    android:layout_weight="1"
+                    android:backgroundTint="#80323232"
+                    android:backgroundTintMode="src_in"
+                    android:hapticFeedbackEnabled="false"
+                    android:insetTop="0dp"
+                    android:insetBottom="0dp"
+                    android:text="^"
+                    android:textSize="24sp"
+                    app:cornerRadius="0dp" />
+
+                <Button
+                    android:id="@+id/btn_sqrt"
+                    android:layout_width="match_parent"
+                    android:layout_height="0dp"
+                    android:layout_weight="1"
+                    android:backgroundTint="#80323232"
+                    android:backgroundTintMode="src_in"
+                    android:hapticFeedbackEnabled="false"
+                    android:insetTop="0dp"
+                    android:insetBottom="0dp"
+                    android:text="√"
+                    android:textSize="24sp"
+                    app:cornerRadius="0dp" />
+
+                <Button
+                    android:id="@+id/btn_del"
+                    android:layout_width="match_parent"
+                    android:layout_height="0dp"
+                    android:layout_weight="2"
+                    android:backgroundTint="#803A2121"
+                    android:backgroundTintMode="src_in"
+                    android:hapticFeedbackEnabled="false"
+                    android:insetTop="0dp"
+                    android:insetBottom="0dp"
+                    app:cornerRadius="0dp"
+                    app:icon="@android:drawable/ic_input_delete"
+                    app:iconGravity="textStart"
+                    app:iconPadding="0dp" />
+
+            </LinearLayout>
         </LinearLayout>
     </LinearLayout>
 
-    <LinearLayout
-        android:id="@+id/linearLayout3"
-        android:layout_width="0dp"
-        android:layout_height="wrap_content"
-        android:orientation="horizontal"
-        app:layout_constraintBottom_toTopOf="@+id/linearLayout2"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent">
-
-        <Button
-            android:id="@+id/button26"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:layout_weight="1"
-            android:backgroundTint="#80505050"
-            android:backgroundTintMode="src_in"
-            android:hapticFeedbackEnabled="false"
-            android:insetTop="0dp"
-            android:insetBottom="0dp"
-            android:text="X"
-            app:cornerRadius="0dp" />
-
-        <Button
-            android:id="@+id/button27"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:layout_weight="1"
-            android:backgroundTint="#80505050"
-            android:backgroundTintMode="src_in"
-            android:hapticFeedbackEnabled="false"
-            android:insetTop="0dp"
-            android:insetBottom="0dp"
-            android:text="="
-            app:cornerRadius="0dp" />
-    </LinearLayout>
-
-    <LinearLayout
-        android:layout_width="0dp"
-        android:layout_height="wrap_content"
-        android:backgroundTint="#4D333333"
-        android:orientation="vertical"
-        app:layout_constraintBottom_toTopOf="@+id/linearLayout3"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent">
-
-        <Button
-            android:id="@+id/button28"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:backgroundTint="#80505050"
-            android:backgroundTintMode="src_in"
-            android:hapticFeedbackEnabled="false"
-            android:insetTop="0dp"
-            android:insetBottom="0dp"
-            android:text="Вычеслить"
-            app:cornerRadius="0dp" />
-    </LinearLayout>
-
     <!--    <EditText-->
-<!--        android:id="@+id/function_in"-->
-<!--        android:layout_width="0dp"-->
-<!--        android:layout_height="wrap_content"-->
-<!--        android:ems="10"-->
-<!--        android:hint="Введите уравнение:"-->
-<!--        android:inputType="textPersonName"-->
-<!--        android:text="y = "-->
-<!--        app:layout_constraintEnd_toEndOf="parent"-->
-<!--        app:layout_constraintStart_toStartOf="parent"-->
-<!--        app:layout_constraintTop_toBottomOf="@+id/graph" />-->
+    <!--        android:id="@+id/function_in"-->
+    <!--        android:layout_width="0dp"-->
+    <!--        android:layout_height="wrap_content"-->
+    <!--        android:ems="10"-->
+    <!--        android:hint="Введите уравнение:"-->
+    <!--        android:inputType="textPersonName"-->
+    <!--        android:text="y = "-->
+    <!--        app:layout_constraintEnd_toEndOf="parent"-->
+    <!--        app:layout_constraintStart_toStartOf="parent"-->
+    <!--        app:layout_constraintTop_toBottomOf="@+id/graph" />-->
 
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values-night/themes.xml b/app/src/main/res/values-night/themes.xml
index 80d3923..5728a0f 100644
--- a/app/src/main/res/values-night/themes.xml
+++ b/app/src/main/res/values-night/themes.xml
@@ -4,11 +4,11 @@
         <!-- Primary brand color. -->
         <item name="colorPrimary">@color/purple_200</item>
         <item name="colorPrimaryVariant">@color/purple_700</item>
-        <item name="colorOnPrimary">@color/black</item>
+        <item name="colorOnPrimary">@color/white</item>
         <!-- Secondary brand color. -->
         <item name="colorSecondary">@color/teal_200</item>
         <item name="colorSecondaryVariant">@color/teal_200</item>
-        <item name="colorOnSecondary">@color/black</item>
+        <item name="colorOnSecondary">@color/white</item>
         <!-- Status bar color. -->
         <item name="android:statusBarColor">?attr/colorPrimaryVariant</item>
         <!-- Customize your theme here. -->
diff --git a/build.gradle b/build.gradle
index 2536974..b2ebb1e 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,6 +1,6 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 plugins {
-    id 'com.android.application' version '7.3.1' apply false
-    id 'com.android.library' version '7.3.1' apply false
+    id 'com.android.application' version '7.4.1' apply false
+    id 'com.android.library' version '7.4.1' apply false
     id 'org.jetbrains.kotlin.android' version '1.7.20' apply false
 }
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 1c6eb41..07bbf9a 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 #Wed Nov 16 21:17:09 MSK 2022
 distributionBase=GRADLE_USER_HOME
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.5-bin.zip
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME