km = int(input())
day_or_night = input()

# taxi
t_begin = 0.70
t_day_tariff = 0.79
t_night_tariff = 0.90

# bus
bus_tariff = 0.09
# b_km_must = 20

# train
train_tariff = 0.06
# t_km_must = 100

if day_or_night == "day":
    if km > 100:
        taxi = t_begin + t_day_tariff * km
        bus = bus_tariff * km
        train = train_tariff * km
        print(min(taxi, bus, train))
    elif km > 20:
        taxi = t_begin + t_day_tariff * km
        bus = bus_tariff * km
        train = train_tariff * 100
        print(min(taxi, bus, train))
    else:
        taxi = t_begin + t_day_tariff * km
        bus = bus_tariff * 20
        train = train_tariff * 100
        print(min(taxi, bus, train))
else:
    if km > 100:
        taxi = t_begin + t_night_tariff * km
        bus = bus_tariff * km
        train = train_tariff * km
        print(min(taxi, bus, train))
    elif km > 20:
        taxi = t_begin + t_night_tariff * km
        bus = bus_tariff * km
        train = train_tariff * 100
        print(min(taxi, bus, train))
    else:
        taxi = t_begin + t_night_tariff * km
        bus = bus_tariff * 20
        train = train_tariff * 100
        print(min(taxi, bus, train))