01.Black Flag

plunder_days = int(input())
daily_plunder = int(input())
expected_plunder = float(input())
gained_plunder = 0


for day in range(1, plunder_days + 1):
    gained_plunder += daily_plunder

    if day % 3 == 0:
        gained_plunder += daily_plunder * 0.50

    if day % 5 == 0:
        gained_plunder -= (daily_plunder * 0.30)


if gained_plunder >= expected_plunder:
    print(f"Ahoy! {gained_plunder:.2f} plunder gained.")
else:
    percentage = gained_plunder / expected_plunder * 100
    print(f"Collected only {percentage:.2f}% of the plunder.")