import java.applet.Applet;
import java.awt.event.*;
import java.awt.*;
public class katse extends Applet implements Runnable, KeyListener{
  int x=0, y=2;
  boolean veel=true;
  public katse(){
    init();
    new Thread(this).start();    
  }
  public void init(){
    addKeyListener(this);    
  }  
  public void run(){
    while(veel){
    for(int x=40; x<600; x=x+y){
    Graphics g=this.getGraphics();
    if(g!=null){           
      g.setColor(Color.black);       
      g.drawOval(x, 90, 20, 20);
      try{Thread.sleep(50);}catch(Exception m){} 
      g.setColor(Color.white);       
      g.drawOval(x, 90, 20, 20);       
    }
    }
    }
  }
   public void keyPressed(KeyEvent e){
    int kood=e.getKeyCode();
    if(kood==KeyEvent.VK_LEFT)y--;
    if(kood==KeyEvent.VK_RIGHT)y++; 
      } 
  public void keyReleased(KeyEvent e){}
  public void keyTyped(KeyEvent e){}
    public static void main(String argumendid[]){
    Frame f=new Frame();
    f.add(new katse());
    f.setSize(700, 300);
    f.setVisible(true);
}
}