public class Callers
{
   public static void main( String args[] )
   {
      PrepaidSimCard globe;
      PrepaidSimCard jasper;
      PrepaidSimCard smart;

      globe = new PrepaidSimCard(); // defaults to a balance of 100 pesos
      jasper = new PrepaidSimCard( 300 );
      smart = new PrepaidSimCard( 200 );

      System.out.println( "Globe balance: " + globe.getBalance() );
      System.out.println( "Jasper balance: " + jasper.getBalance() );
      System.out.println( "Smart balance: " + smart.getBalance() );
      System.out.println( "---" );

      globe.sendText();      // 1 peso per text sent
      globe.makeCall( 8 );   // 8 pesos per minute
      jasper.makeCall( 30 ); 
      for ( int i = 0; i < 35; i++ )
      {
         jasper.sendText();
         smart.sendText();
      }

      System.out.println( "Globe balance: " + globe.getBalance() );
      System.out.println( "Jasper balance: " + jasper.getBalance() );
      System.out.println( "Smart balance: " + smart.getBalance() );
      System.out.println( "---" );

      jasper.makeCall( 20 ); // not enough money for this call, balance
                             // should be less than 8 pesos afterwards
      smart.makeCall( 20 );
      smart.makeCall( 1 );   // call not allowed - 5 pesos left
      smart.sendText();      // but text allowed

      System.out.println( "Globe balance: " + globe.getBalance() );
      System.out.println( "Jasper balance: " + jasper.getBalance() );
      System.out.println( "Smart balance: " + smart.getBalance() );
      System.out.println( "---" );
   }
}