Easter Party

guest = int(input())
envelope = float(input())
budget = float(input())

total_sum = guest * envelope

if 10 <= guest <= 15:
    total_sum *= 0.85
elif 15 < guest <= 20:
    total_sum *= 0.8
elif guest > 20:
    total_sum *= 0.75

total_sum += budget / 10

if budget >= total_sum:
    print(f"It is party time! {budget - total_sum:.2f} leva left.")
else:
    print(f"No party! {total_sum - budget:.2f} leva needed.")