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;
    }

}