diff --git a/.idea/artifacts/Calculator_jar.xml b/.idea/artifacts/Calculator_jar.xml
new file mode 100644
index 0000000..849002b
--- /dev/null
+++ b/.idea/artifacts/Calculator_jar.xml
@@ -0,0 +1,9 @@
+<component name="ArtifactManager">
+  <artifact type="jar" name="Calculator:jar">
+    <output-path>$PROJECT_DIR$/out/artifacts/Calculator_jar</output-path>
+    <root id="archive" name="Calculator.jar">
+      <element id="module-output" name="Calculator" />
+      <element id="extracted-dir" path="$MAVEN_REPOSITORY$/org/mariuszgromada/math/MathParser.org-mXparser/5.2.1/MathParser.org-mXparser-5.2.1.jar" path-in-jar="/" />
+    </root>
+  </artifact>
+</component>
\ No newline at end of file
diff --git a/.idea/gradle.xml b/.idea/gradle.xml
new file mode 100644
index 0000000..3e3960b
--- /dev/null
+++ b/.idea/gradle.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
+</project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 4444b22..43b1638 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_22" default="true" project-jdk-name="openjdk-22" project-jdk-type="JavaSDK">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="temurin-17" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/src/META-INF/MANIFEST.MF b/src/META-INF/MANIFEST.MF
new file mode 100644
index 0000000..9aa4654
--- /dev/null
+++ b/src/META-INF/MANIFEST.MF
@@ -0,0 +1,3 @@
+Manifest-Version: 1.0
+Main-Class: calculator.Calculator
+
diff --git a/src/calculator/Calculator.java b/src/calculator/Calculator.java
index 839cd15..2fccfb9 100644
--- a/src/calculator/Calculator.java
+++ b/src/calculator/Calculator.java
@@ -69,8 +69,8 @@ public void componentResized(ComponentEvent e) {
     }
     public void UpdateHistoryScroll(int scrollValue){
         int shift = -scrollValue * historyFontSize;
-        if (history.getFirst().getLabel().getY() + shift > 20) return;
-        if (history.getLast().getLabel().getY() + shift < historyPanel.getHeight() - 20) return;
+        if (Utils.getFirst(history).getLabel().getY() + shift > 20) return;
+        if (Utils.getLast(history).getLabel().getY() + shift < historyPanel.getHeight() - 20) return;
         for (HistoryToken token : history){
             token.getLabel().setBounds(token.getLabel().getX(), token.getLabel().getY() + shift, token.getLabel().getWidth(), token.getLabel().getHeight());
         }
@@ -214,7 +214,7 @@ private void adjustHistoryPanel(){
     private List<CalculatorButton> getCalculatorButtons() {
         List<CalculatorButton> buttons = new ArrayList<>();
         buttons.add(new CalculatorButton("=", "", new Color(217, 137, 91), true));
-        buttons.getLast().jButton.addActionListener(new ActionListener() {
+        Utils.getLast(buttons).jButton.addActionListener(new ActionListener() {
             @Override
             public void actionPerformed(ActionEvent e) {
                 evaluate();
@@ -222,7 +222,7 @@ public void actionPerformed(ActionEvent e) {
         });
 
         buttons.add(new CalculatorButton("C", "", new Color(117, 117, 117), true));
-        buttons.getLast().jButton.addActionListener(new ActionListener() {
+        Utils.getLast(buttons).jButton.addActionListener(new ActionListener() {
             @Override
             public void actionPerformed(ActionEvent e) {
                 textField.setText("");
@@ -230,7 +230,7 @@ public void actionPerformed(ActionEvent e) {
         });
 
         buttons.add(new CalculatorButton("del", "", new Color(117, 117, 117), true));
-        buttons.getLast().jButton.addActionListener(new ActionListener() {
+        Utils.getLast(buttons).jButton.addActionListener(new ActionListener() {
             @Override
             public void actionPerformed(ActionEvent e) {
                 textField.setText(textField.getText().isEmpty() ? "" : textField.getText().substring(0, textField.getText().length()-1) );
@@ -238,7 +238,7 @@ public void actionPerformed(ActionEvent e) {
         });
 
         buttons.add(new CalculatorButton("ans", "", new Color(117, 117, 117), true));
-        buttons.getLast().jButton.addActionListener(new ActionListener() {
+        Utils.getLast(buttons).jButton.addActionListener(new ActionListener() {
             @Override
             public void actionPerformed(ActionEvent e) {
                 textField.setText(textField.getText() + (history.isEmpty() ? "" : history.get(history.size()-1).getValue()));
@@ -246,7 +246,7 @@ public void actionPerformed(ActionEvent e) {
         });
 
         buttons.add(new CalculatorButton("last", "", new Color(117, 117, 117), true));
-        buttons.getLast().jButton.addActionListener(new ActionListener() {
+        Utils.getLast(buttons).jButton.addActionListener(new ActionListener() {
             @Override
             public void actionPerformed(ActionEvent e) {
                 textField.setText(textField.getText() + (history.isEmpty() ? "" : history.get(history.size()-1).getExpression()));
@@ -254,7 +254,7 @@ public void actionPerformed(ActionEvent e) {
         });
 
         buttons.add(new CalculatorButton(solver.degMod ? "deg" : "rad", "", new Color(117, 117, 117), true));
-        buttons.getLast().jButton.addActionListener(new ActionListener() {
+        Utils.getLast(buttons).jButton.addActionListener(new ActionListener() {
             @Override
             public void actionPerformed(ActionEvent e) {
                 solver.setDegMod(!solver.degMod);
@@ -283,7 +283,7 @@ public void actionPerformed(ActionEvent e) {
         buttons.add(new CalculatorButton(".", ".", new Color(135, 222, 184)));
         buttons.add(new CalculatorButton("0", "0", new Color(135, 222, 184)));
         buttons.add(new CalculatorButton("-", "", new Color(135, 222, 184), true));
-        buttons.getLast().jButton.addActionListener(new ActionListener() {
+        Utils.getLast(buttons).jButton.addActionListener(new ActionListener() {
             @Override
             public void actionPerformed(ActionEvent e) {
                 textField.setText("-(" + textField.getText() + ")");
diff --git a/src/calculator/Utils.java b/src/calculator/Utils.java
new file mode 100644
index 0000000..5c69f82
--- /dev/null
+++ b/src/calculator/Utils.java
@@ -0,0 +1,19 @@
+package calculator;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Utils {
+    public static <T> T getFirst(ArrayList<T> list){
+        return list.get(0);
+    }
+    public static <T> T getLast(ArrayList<T> list){
+        return list.get(list.size() - 1);
+    }
+    public static <T> T getFirst(List<T> list){
+        return list.get(0);
+    }
+    public static <T> T getLast(List<T> list){
+        return list.get(list.size() - 1);
+    }
+}