Clever Lily

age = int(input())
washer = float(input())
toy_price = int(input())
toys = 0
money = 0
total = 0
even_years = 0

for i in range(1, age + 1):
  if i % 2 == 0:
    money += 10 * (i / 2)
    even_years += 1
  else:
    toys += 1

total = (money - even_years) + toys * toy_price
if total >= washer:
  print(f"Yes! {(total - washer):.2f}")

else:
  print(f"No! {abs(total - washer):.2f}")