// DotsAndDollars.java  (c) 2005 Kari Laitinen

//  http://www.naturalprogramming.com

//  2004-09-14  File created.
//  2005-05-15  Last modification.

import  java.util.* ;

class ThreadToPrintDots extends Thread
{
   boolean  must_print_dots  =  true ;

   public void stop_this_thread()
   {
      must_print_dots  =  false ;
   }

   public void run()
   {
      while ( must_print_dots  ==  true )
      {
         try
         {
            Thread.sleep( 1000 ) ; // Wait one second.
         }
         catch ( InterruptedException caught_exception )
         {
         }
      
         System.out.print( " ." ) ;
      }
   }
}

class ThreadToPrintDollarSigns extends Thread
{
   boolean  must_print_dollar_signs  =  true ;

   public void stop_this_thread()
   {
      must_print_dollar_signs  =  false ;
   }

   public void run()
   {
      while ( must_print_dollar_signs  ==  true )
      {
         try
         {
            Thread.sleep( 4050 ) ; // Wait 4.05 seconds.
         }
         catch ( InterruptedException caught_exception )
         {
         }
      
         System.out.print( " $" ) ;
      }
   }
}

class DotsAndDollars
{
   public static void main( String[] not_in_use )
   {
      Scanner keyboard = new Scanner( System.in ) ;

      ThreadToPrintDots  thread_to_print_dots  =  new  ThreadToPrintDots() ;
      ThreadToPrintDollarSigns  thread_to_print_dollar_signs  =
                                           new  ThreadToPrintDollarSigns() ;
      thread_to_print_dots.start() ;
      thread_to_print_dollar_signs.start() ;

      System.out.print( "\n Press the Enter key to stop the program. \n\n" ) ;

      String  any_string_from_keyboard  =  keyboard.nextLine() ;

      thread_to_print_dots.stop_this_thread() ;
      thread_to_print_dollar_signs.stop_this_thread() ;
   }
}