/* Listing2210.java */

public class Listing2210
extends Thread
{
  static int cnt = 0;

  public static void main(String[] args)
  {
    Thread t1 = new Listing2210();
    Thread t2 = new Listing2210();
    t1.start();
    t2.start();
  }

  public void run()
  {
    while (true) {
      synchronized (getClass()) {
        System.out.println(cnt++);
      }
    }
  }
}