public class ?? {

     public static void main(String[] args) {
         (new ??()).loop();
     }

     public void loop() {
         int i = 0;
         while (true) {
              System.out.println("Looping ??" + i);
              ping();
              i++;
              try {
                  Thread.sleep(1000);
              } catch (InterruptedException e) {
              }
         }
     }

     public void ping() {
         for (int i = (int)(Math.random() * 4) + 2;i > 0;i--) {
              pong();
         }
     }

     public void pong() {
         System.out.println("ping pong");
     }             
}