fruit_shop

fruit = input()
day_of_the_week = input()
quantity = float(input())
day_is_valid = True
fruit_is_valid = True
price = 0
total_sum = 0

if day_of_the_week == "Monday"\
        or day_of_the_week == "Tuesday"\
        or day_of_the_week == "Wednesday"\
        or day_of_the_week == "Thursday"\
        or day_of_the_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
            else:
                fruit_is_valid = False
elif day_of_the_week == "Saturday"\
            or day_of_the_week == "Sunday":
            if fruit == "banana":
                price = 2.70
            elif fruit == "apple":
                price = 1.25
            elif fruit == "orange":
                price = 0.90
            elif fruit == "grapefruit":
                price = 1.60
            elif fruit == "kiwi":
                price = 3.00
            elif fruit == "pineapple":
                price = 5.60
            elif fruit == "grapes":
                price = 4.20
            else:
                fruit_is_valid = False
else:
    day_is_valid = False
if fruit_is_valid and day_is_valid:
    total_sum = (quantity * price)
    print(f'{total_sum:.2f}')
else:
    print("error")