using System;

public class Program

{

    public static void Main()

    {

var product = Console.ReadLine().ToLower();

var town = Console.ReadLine().ToLower();

var quantity = double.Parse(Console.ReadLine());

if (town == "sofia")

{

   if (product == "coffee") 

      { Console.WriteLine(0.50 * quantity); }

   if (product == "water") 

      { Console.WriteLine(0.80 * quantity); }

    if (product == "beer") 

      { Console.WriteLine(1.20 * quantity); }

    if (product == "sweets") 

      { Console.WriteLine(1.45 * quantity); }

    if (product == "peanuts") 

      { Console.WriteLine(1.60 * quantity); }

    }

if (town == "varna")   

{

   if (product == "coffee") 

      { Console.WriteLine(0.45 * quantity); }

   if (product == "water") 

      { Console.WriteLine(0.70 * quantity); }

    if (product == "beer") 

      { Console.WriteLine(1.10 * quantity); }

    if (product == "sweets") 

      { Console.WriteLine(1.35 * quantity); }

    if (product == "peanuts") 

      { Console.WriteLine(1.55 * quantity); }

    }       

if (town == "plovdiv")  

{

   if (product == "coffee") 

      { Console.WriteLine(0.40 * quantity); }

   if (product == "water") 

      { Console.WriteLine(0.70 * quantity); }

    if (product == "beer") 

      { Console.WriteLine(1.15 * quantity); }

    if (product == "sweets") 

      { Console.WriteLine(1.30 * quantity); }

    if (product == "peanuts") 

      { Console.WriteLine(1.50 * quantity); }

    }       

    }

}