fruit = input()
day_of_the_week = input()
quantity = float(input())

day_of_the_week_is_valid = True
fruit_is_valid = True
price = 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 = 2.50
    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
    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_of_the_week_is_valid = False
if day_of_the_week_is_valid and fruit_is_valid:
    print(f'{price * quantity:.2f}')
else:
    print('error')