import java.awt.*;
import java.applet.Applet;

public class Clock extends Applet {

    private Second second;
    private Minute minute;

    public void init() {
        TickTock minuteTick = new TickTock();

        minute = new Minute(minuteTick, this);
        minute.start();

        second = new Second(minuteTick, this);
        second.start();
    }

    public void paint(Graphics g) {
        minute.display(g);
        second.display(g);
    }
}

class Second extends Thread {

    private int seconds = 0;

    private TickTock minuteTick;
    private Applet applet;

    public Second(TickTock minuteTick, Applet applet) {
        this.minuteTick = minuteTick;
        this.applet = applet;
    }

    public void run() {
        while(true) {
            try {
                Thread.sleep(1000);
            }
            catch (InterruptedException e) {
                System.err.println("Exception");
            }
            if (seconds == 59) {
                minuteTick.tick();
                seconds = 0;
            }
            else seconds++;
            applet.repaint();
        }
    }

    public void display(Graphics g) {
        g.clearRect(10, 0, 100, 20);
        g.drawString(seconds + " seconds", 10, 20);
    }
}

class Minute extends Thread {

    private int minutes = 0;
    private TickTock minuteTick;
    private Applet applet;

    public Minute(TickTock minuteTick, Applet applet) {
        this.minuteTick = minuteTick;
        this.applet = applet;
    }

    public void run() {
        while(true) {
            minuteTick.waitForTick();
            if (minutes == 59) {
                minutes = 0;
            }
            else
                minutes++;
                applet.repaint();
        }
    }

    public void display(Graphics g) {
        g.clearRect(10, 20, 100, 20);
        g.drawString(minutes + " minutes", 10, 40);
    }
}

class TickTock {

    private boolean tickHappens = false;

    public synchronized void waitForTick() {
        while (!tickHappens)
            try {
                wait();
            }
            catch (InterruptedException e) {
                System.err.println("Exception");
            }
        tickHappens = false;
    }

    public synchronized void tick() {
        tickHappens = true;
        notify();
    }
}