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diff --git a/main$3.class b/main$3.class
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diff --git a/main.ctxt b/main.ctxt
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+#BlueJ class context
+comment0.target=main
+comment1.params=a
+comment1.target=void\ answer(java.lang.String)
+comment2.params=d\ t\ f
+comment2.target=void\ msg(java.lang.String,\ java.lang.String,\ int)
+comment3.params=sender
+comment3.target=void\ sbl(javax.swing.JButton)
+comment4.params=e
+comment4.target=void\ actionPerformed(java.awt.event.ActionEvent)
+comment5.params=
+comment5.target=void\ randomize()
+comment6.params=args
+comment6.target=void\ main(java.lang.String[])
+comment7.params=e
+comment7.target=void\ actionPerformed(java.awt.event.ActionEvent)
+comment8.params=e
+comment8.target=void\ actionPerformed(java.awt.event.ActionEvent)
+numComments=9
diff --git a/main.java b/main.java
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+++ b/main.java
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+
+/**
+ * Write a description of main here.
+ * 
+ * @author (your name) 
+ * @version (a version number or a date)
+ */
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.*;
+import java.util.*;
+import org.mariuszgromada.math.mxparser.*;
+public class main {
+    private static JTextArea ans;
+    private static String pstr = "";
+    private static ArrayList<Component> carr = new ArrayList<Component>();
+    private static JFrame window;
+    private static Font f = new Font("Comic Sans MS", Font.PLAIN, 20);
+    private static long cps = 0;
+    private static long lt = 0;
+    private static boolean first = false;
+    private static void answer(String a) {
+        ans.setText(a);
+        pstr = "";
+    }
+    private static void msg(String d, String t, int f) {
+        JOptionPane.showMessageDialog(window, d, t, f);
+    }
+    private static void sbl(JButton sender) {
+        sender.addActionListener(new ActionListener() {
+            public void actionPerformed(ActionEvent e) {
+                if (System.currentTimeMillis() - lt > 5000) {
+                    cps = 0;
+                    lt = System.currentTimeMillis();
+                } else {
+                    cps++;
+                    if (cps > 5) {
+                        msg("You clicked too fast!", "Oops", JOptionPane.INFORMATION_MESSAGE);
+                        cps = 0;
+                        lt = System.currentTimeMillis();
+                    }
+                }
+                pstr += sender.getText();
+                ans.setText(pstr);
+            }
+        });
+    }
+    private static void randomize() {
+        window.getContentPane().removeAll();
+        if (first) {
+            Collections.shuffle(carr);
+        } else {
+            first = true;
+        }
+        for (int i=0; i < carr.size(); i++) {
+            window.add(carr.get(i));
+        }
+        window.validate();
+    }
+    
+    public static void main(String[] args) {
+        window = new JFrame("Calculator");
+        License.iConfirmNonCommercialUse("qwert");
+        window.setSize(300, 400);
+        window.setResizable(false);
+        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        window.setLayout(new GridLayout(0,4));
+        ans = new JTextArea("0");
+        ans.setEditable(false);
+        ans.setLineWrap(true);
+        carr.add(ans);
+        
+        JButton add = new JButton("+");
+        add.setFont(f);
+        sbl(add);
+        carr.add(add);
+        JButton subtract = new JButton("-");
+        subtract.setFont(f);
+        sbl(subtract);
+        carr.add(subtract);
+        JButton multiply = new JButton("*");
+        multiply.setFont(f);
+        sbl(multiply);
+        carr.add(multiply);
+        JButton divide = new JButton("/");
+        divide.setFont(f);
+        sbl(divide);
+        carr.add(divide);
+        
+        for (int i=0; i < 10; i++) {
+            JButton b = new JButton(String.valueOf(i));
+            b.setFont(f);
+            sbl(b);
+            b.setBackground(Color.LIGHT_GRAY);
+            carr.add(b);
+        }
+        
+        JButton clear = new JButton("C");
+        clear.setFont(f);
+        clear.addActionListener(new ActionListener() {
+            public void actionPerformed(ActionEvent e) {
+                randomize();
+                pstr = "";
+                ans.setText("0");
+            }
+        });
+        carr.add(clear);
+        
+        JButton equal = new JButton("=");
+        equal.setFont(f);
+        equal.setBackground(Color.RED);
+        equal.addActionListener(new ActionListener() {
+            public void actionPerformed(ActionEvent e) {
+                randomize();
+                String vo = String.valueOf(new Expression(pstr).calculate());
+                if (vo == "NaN") {
+                    msg("Calculation error, quitting.", "Oops", JOptionPane.ERROR_MESSAGE);
+                    System.exit(1);
+                }
+                ans.setText(vo);
+                pstr = "";
+            }
+        });
+        carr.add(equal);
+        
+        randomize();
+        window.setVisible(true);
+    }
+}