fruit = input()
day_of_week = input()
quantity = float(input())

price = 0

if day_of_week == "Monday" or day_of_week == "Tuesday" or day_of_week == "Wednesday" or day_of_week == "Thursday"\
        or day_of_week == "Friday":
    if fruit == "banana":
        price = 2.5
    elif fruit == "apple":
        price = 1.2
    elif fruit == "orange":
        price = 0.85
    elif fruit == "grapefruit":
        price = 1.45
    elif fruit == "kiwi":
        price = 2.7
    elif fruit == "pineapple":
        price = 5.5
    elif fruit == "grapes":
        price = 3.85

elif day_of_week == "Saturday" or day_of_week == "Sunday":
    if fruit == "banana":
        price = 2.7
    elif fruit == "apple":
        price = 1.25
    elif fruit == "orange":
        price = 0.9
    elif fruit == "grapefruit":
        price = 1.60
    elif fruit == "kiwi":
        price = 3.00
    elif fruit == "pineapple":
        price = 5.6
    elif fruit == "grapes":
        price = 4.2
if price == 0.00:
    print("error")
else:
    sum = (f'{price * quantity:.2f}')
    print(sum)