fruit shop

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 = 2.50
    elif fruit == 'apple':
        price = 1.20
    elif fruit == 'orange':
        price = 0.85
    elif fruit == 'grapefruit':
        price = 1.45
    elif fruit == 'kiwi':
        price = 2.70
    elif fruit == 'pineapple':
        price = 5.50
    elif fruit == 'grapes':
        price = 3.85

elif day_of_week == 'Saturday' or day_of_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

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