lenght = int(input())
width = int(input())

cake_size = lenght * width
is_over = False
count = input()

while not count == "STOP":
    count = int(count)
    cake_size -= count

    if cake_size <= 0:
        is_over = True
        print(f"No more cake left! You need {cake_size * -1} pieces more.")
        break
    count = input()
if not is_over:
    print(f"{cake_size} pieces are left.")