product = input()
city = input()
quantity = int(input())

if city == "Sofia":
    if product == "coffee":
        price = quantity * 0.5
        if product == "water":
            price = quantity * 0.8
            if product == "beer":
                price = quantity * 1.2
                if product == "sweets":
                    price = quantity * 1.45
                    if product == "peanuts":
                        price = quantity * 1.6

elif city == "Plovdiv":
    if product == "coffee":
        price = quantity * 0.4
        if product == "water":
            price = quantity * 0.7
            if product == "beer":
                price = quantity * 1.15
                if product == "sweets":
                    price = quantity * 1.30
                    if product == "peanuts":
                        price = quantity * 1.50

elif city == "Varna":
    if product == "coffee":
        price = quantity * 0.45
        if product == "water":
            price = quantity * 0.7
            if product == "beer":
                price = quantity * 1.10
                if product == "sweets":
                    price = quantity * 1.35
                    if product == "peanuts":
                        price = quantity * 1.55

print(price)