public class CashDispenser
{
    private final static int INITIAL_COUNT=500;
    private int count;

    public CashDispenser()
    {
        count=INITIAL_COUNT;
    }

    public void dispenseCash(int amount)
    {
        int billsRequired=amount/20;
        count -=billsRequired;
    }

    public boolean isSufficientCashAvailable(int amount)
    {
        int billsRequired=amount/20;
        if(count>=billsRequired)
            return true;
        else
            return false;
    }
}