fruit = input()
week_day = input()
quantity = float(input())

price = 0
if week_day == 'Monday' \
        or week_day == 'Tuesday' \
        or week_day == 'Wednesday' \
        or week_day == 'Thursday' \
        or week_day ==  '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 week_day == 'Saturday' or week_day == 'Sunday':
    if fruit == 'banana':
        price == 2.7
    elif fruit == 'apple':
        price = 1.25
    elif fruit == 'orange':
        price = 0.90
    elif fruit == 'grapefruit':
        price = 1.6
    elif fruit == 'kiwi':
        price = 3
    elif fruit == 'pineapple':
        price = 5.6
    elif fruit == 'grapes':
        price = 4.2


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