product = input()
town = input()
quanity = float(input())

if town == "Sofia":
    if product == "coffee":
        print(quanity*0.50)
    elif product == "water":
        print(quanity*0.80)
    elif product == "beer":
        print(quanity*1.20)
    elif product == "sweets":
        print(quanity*1.45)
    elif product == "peanuts":
        print(quanity*1.60)
elif town == "Plovdiv":
    if product == "coffee":
        print(quanity*0.40)
    elif product == "water":
        print(quanity*0.70)
    elif product == "beer":
        print(quanity*1.15)
    elif product == "sweets":
        print(quanity*1.30)
    elif product == "peanuts":
        print(quanity*1.50)
elif town == "Varna":
    if product == "coffee":
        print(quanity*0.45)
    elif product == "water":
        print(quanity*0.70)
    elif product == "beer":
        print(quanity*1.10)
    elif product == "sweets":
        print(quanity*1.35)
    elif product == "peanuts":
        print(quanity*1.55)