years = int(input())
machine_price = float(input())
toy_price = float(input())
toys_count = 0
money_amount = 0
for year in range(1, years + 1):
    if year % 2 == 0:
        money_amount += year / 2 * 10
        money_amount -= 1
    else:
         toys_count += 1
toys_price = toys_count * toy_price
total_amount = toys_price + money_amount
if total_amount >= machine_price:
    print(f'Yes! {total_amount - machine_price:.2f}')
else:
    print(f'No! {machine_price - total_amount:.2f}')