public class TFMath { 
 
  public static void main(String[] args) { 
    new TFrame(); 
  } 
 
} 
 
class TFrame extends Frame{ 
  TextField tf1, tf2, tf3; 
  TFrame(){ 
    tf1 = new TextField("", 10); 
    tf2 = new TextField("", 10); 
    tf3 = new TextField("", 12); 
    Label lbladd = new Label("+"); 
    Button btneq = new Button("="); 
    Monitor mnt = new Monitor(this); 
    btneq.addActionListener(mnt); 
    super.add(tf1); 
    super.add(lbladd); 
    super.add(tf2); 
    super.add(btneq); 
    super.add(tf3); 
    super.setLayout(new FlowLayout(FlowLayout.CENTER)); 
    super.pack(); 
    super.setBounds(400, 400, 500, 300); 
    super.setBackground(Color.DARK_GRAY); 
    super.setVisible(true); 
  } 
} 
 
class Monitor implements ActionListener{ 
  TFrame tf = null; 
  public Monitor(TFrame tf){ 
    this.tf = tf; 
  } 
  public void actionPerformed(ActionEvent e){ 
    int num1 = Integer.parseInt(tf.tf1.getText()); 
    int num2 = Integer.parseInt(tf.tf2.getText()); 
    int num3 = num1 + num2; 
    tf.tf3.setText(String.valueOf(num3)); 
  } 
}