import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Oppgave1 {
    
    public static void main(String[] args) {

        JFrame vindu = new JFrame("Oppgave 1");
        vindu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel = new JPanel(new GridLayout(2, 3));

        for (int i = 1; i <= 6 ; i++) {
            Rute nyKnapp = new Rute(i+"");
            panel.add(nyKnapp);
        }

        vindu.add(panel);

        vindu.pack();
        vindu.setVisible(true);
        
    }
}

class Rute extends JButton {

    String tall;

    class Klikk implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            if (getText().equals(tall)) {
                setText(":)");
            }
            else {
                setText(tall );
            }
        }
    }

    Rute(String t) {
        super(t);
        tall = t;
        addActionListener(new Klikk());
    }
}