2 Bike Race

# 2. Вело състезание

num_juniors = int(input())
num_seniors = int(input())
route = str(input())

junior_ticket = 0
senior_ticket = 0
total_tickets = num_juniors + num_seniors

if route == "trail":
    junior_ticket = 5.50
    senior_ticket = 7
elif route == "cross-country":
    junior_ticket = 8
    senior_ticket = 9.50
elif route == "downhill":
    junior_ticket = 12.25
    senior_ticket = 13.75
elif route == "road":
    junior_ticket = 20
    senior_ticket = 21.50

income = num_juniors * junior_ticket + num_seniors * senior_ticket

if total_tickets >= 50 and route == "cross-country":
    income *= 0.75

expense = income * 0.05
charitable_amount = income - expense
print(f"{charitable_amount:.2f}")