public class Coins {
    public Coins(int coins) {

    }

    public int getCoinAmount() {
        return 0;
    }

    public void addCoin(int coins) throws NegativAmountException{
        throw new NegativAmountException();
    }

    public boolean removeCoin(int coins) throws NegativAmountException{
        throw new NegativAmountException();
    }

    public boolean changeCoinAmmount(int coins) {
        return false;
    }
}