public class HelloWorld{

   public static void main(String []args)throws IOException                                                     {
    try {
      for(int i=0;i<24;i++)
      {
         for(int j=0;j<60;j++)
         {
            for(int k=0;k<60;k++)
            {
             clrscr();
             System.out.print(i+":"+j+":"+k);
             Thread.currentThread().sleep(1000);
            /* if(kbhit())
             exit(0);*/
            } 
         }
      }
     }