fruit_shop

fruit = input().lower()
day = input().lower()
quantity = float(input())

price = 0
if "Monday" == day or "Tuesday" == day or "Wednesday" == day\
        or "Thursday" == day or "Friday" == day:
    if "banana" == fruit:
        price = 2.50
    elif "apple" == fruit:
        price = 1.20
    elif "orange" == fruit:
        price = 0.85
    elif "grapefruit" == fruit:
        price = 1.45
    elif "kiwi" == fruit:
        price = 2.70
    elif "pineapple" == fruit:
        price = 5.50
    elif "grapes" == fruit:
        price = 3.85

elif "Saturday" == day or "Sunday" == day:
    if "banana" == fruit:
        price = 2.70
    elif "apple" == fruit:
        price = 1.25
    elif "orange" == fruit:
        price = 0.90
    elif "grapefruit" == fruit:
        price = 1.60
    elif "kiwi" == fruit:
        price = 3.00
    elif "pineapple" == fruit:
        price = 5.60
    elif "grapes" == fruit:
        price = 4.20

if price == 0:
    print("error")
else:
    price = price * quantity
    print(f'{price:.2f}')