fruit

fruit = input()
day = input()
qantity = float(input())
price_of_fruit = 0

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

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

if price_of_fruit == 0:
    print('error')
else:
    total = price_of_fruit * qantity
    print(f"{total:.2f}")