04. Clever Lily

age = int(input())
machine = float(input())
toy_price = float(input())
total_sum = 0
toy = 0
birthday = 10

for i in range(1, age + 1):
    if i % 2 == 0:
        total_sum += birthday - 1
        birthday += 10
    else:
        toy += 1

total_sum += toy * toy_price

if total_sum >= machine:
    print(f'Yes! {total_sum - machine:.2f}')
else:
    print(f'No! {machine - total_sum:.2f}')