using System;

public class Program

{

    public static void Main()

    {

                    string city = Console.ReadLine();

            string product = Console.ReadLine();

            int quantity = int.Parse(Console.ReadLine());

            double prise = 0;

            if (city == "Sofia")

            {

                if (product == "water")

                    prise = 0.80;

                if (product == "cofee")

                    prise = 0.50;

                if (product == "beer")

                    prise = 1.20;

                if (product == "sweets")

                    prise = 1.45;

                if (product == "peanuts")

                    prise = 1.60;

            }

            if (city == "Plovdiv")

            {

                if (product == "water")

                    prise = 0.70;

                if (product == "cofee")

                    prise = 0.40;

                if (product == "beer")

                    prise = 1.15;

                if (product == "sweets")

                    prise = 1.30;

                if (product == "peanuts")

                    prise = 1.50;

            }

            if (city == "Varna")

            {

                if (product == "water")

                    prise = 0.70;

                if (product == "cofee")

                    prise = 0.45;

                if (product == "beer")

                    prise = 1.10;

                if (product == "sweets")

                    prise = 1.35;

                if (product == "peanuts")

                    prise = 1.55;

            }

            double totalprise = prise * quantity;

            Console.WriteLine(totalprise);

    }

}