6. Cake

width=int(input())
length=int(input())
cake_size=width*length


while cake_size>0:
    current_pieces_from_cake=input()

    if current_pieces_from_cake=="STOP":
        break
    cake_size-=int(current_pieces_from_cake)
if cake_size>=0:
    print(f"{cake_size} pieces are left.")
else:
    print(f"No more cake left! You need {abs(cake_size)} pieces more.")