transport

kilometers = int(input())
time_of_day = str(input())

taxi_price_day = 0.70 + kilometers * 0.79
taxi_price_night = 0.70 + kilometers * 0.9
bus_price = kilometers * 0.09
train_price = kilometers * 0.06

if time_of_day == "day" and kilometers < 20:
    print(f'{taxi_price_day:.2f}')
elif time_of_day == "night" and kilometers < 20:
    print(f'{taxi_price_night:.2f}')
elif 20 <= kilometers < 100:
    print(f'{bus_price:.2f}')
else:
    print(f'{train_price:.2f}')