public class CashDispenser
{
    // the default initial number of bills in the cash dispenser
    private final static int INITIAL_COUNT = 500;
    private int count;      // number of $20 bills remaining

    // no-argument CashDispenser constructor initializes count to default
    public CashDispenser(){
        count = INITIAL_COUNT;  // set count attribute to default
    }   // end CashDispenser constructor

    // simulates dispensing of specified amount of cash
    public void dispenseCash(int amount){
        int billsRequired = amount / 20;    // number of $20 bills required
        count -= billsRequired;     // update the count of bills
    }   // end method dispenseCash

    // indicates whether cash dispenser can dispense desired amount
    public boolean isSufficientCashAvailable(int amount){
        int billsRequired = amount / 20;

        if(count >= billsRequired){
            return true;    // enough bills required
        }
        else{
            return false;   // not enough bills required
        }
    }   // end method isSufficientCashAvailable
}   // end class CashDispenser