class Cash {

  private int amount;

  //plus
  void plus(int addend) {
    amount += addend;
  }

  //minus
  boolean minus(int subtrahend) {<FILL_FUNCTION_BODY>}

  //count
  int count() {
    return amount;
  }
}

    if (amount >= subtrahend) {
      amount -= subtrahend;
      return true;
    } else {
      return false;
    }
  
<no_super_class>