Clever Lily

age = int(input())
laundry_price = float(input())
toy_price = int(input())

money = 0
for i in range(1, age + 1):
    money += i * 5 - 1 if i % 2 == 0 else toy_price
    # if i % 2 == 0:
    #     money += i * 5 - 1
    # else:
    #     money += toy_price

result = abs(money-laundry_price)
if money < laundry_price:
    print(f"No! {result:.2f}")
else:
    print(f"Yes! {result:.2f}")