using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Shop
{
    class Program
    {
        static void Main(string[] args)
        {

            var product = Console.ReadLine().ToLower();
            var town = Console.ReadLine().ToLower();
            var quantity = double.Parse(Console.ReadLine());
            var TotalPrice = 1d;

            if (town == "Sofia")
            {
                if (product == "coffee")
                {
                    TotalPrice = quantity * 0.50d;
                }
                else if (product == "water")
                {
                    TotalPrice = quantity * 0.80d;
                }
                else if (product == "beer")
                {
                    TotalPrice = quantity * 1.20d;
                }
                else if (product == "sweets")
                {
                    TotalPrice = quantity * 1.45d;
                }
                else if (product == "peanuts")
                {
                    TotalPrice = quantity * 1.60d;
                }



            }
            if (town == "Povdiv")
            {
                if (product == "coffee")
                {
                    TotalPrice = quantity * 0.40d;
                }
                else if (product == "water")
                {
                    TotalPrice = quantity * 0.70d;
                }
                else if (product == "beer")
                {
                    TotalPrice = quantity * 1.15d;
                }
                else if (product == "sweets")
                {
                    TotalPrice = quantity * 1.30d;
                }
                else if (product == "peanuts")
                {
                    TotalPrice = quantity * 1.50d;
                }


            }


            if (town == "Varna")
            {
                if (product == "coffee")
                {
                    TotalPrice = quantity * 0.45d;
                }
                else if (product == "water")
                {
                    TotalPrice = quantity * 0.70d;
                }
                else if (product == "beer")
                {
                    TotalPrice = quantity * 1.10d;
                }
                else if (product == "sweets")
                {
                    TotalPrice = quantity * 1.35d;
                }
                else if (product == "peanuts")
                {
                    TotalPrice = quantity * 1.55d;
                }
            }

            Console.WriteLine(Math.Round(TotalPrice, (3)));


        }

    }
}