using System;

class Program
{
    static void Main()
    {
        string town = Console.ReadLine().ToLower();
        double sales = double.Parse(Console.ReadLine());
        var comission = -1.0;

        if (town == "sofia")
        {
            if (0 <= sales & sales <= 500)
            {
                Console.WriteLine(sales * 5 / 100);
            }
            else if (500 < sales & sales <= 1000)
            {
                Console.WriteLine(sales * 7 / 100);
            }
            else if (1000 < sales & sales <= 10000)
            {
                Console.WriteLine(sales * 8 / 100);
            }
            else if (sales > 10000)
            {
                Console.WriteLine(sales * 12 / 100);
            }
            else if (sales < 0)
            {
                Console.WriteLine("error");
            }
            else if (comission == -1.0)
            {
                Console.WriteLine("{0:f2}", sales * comission);
            }
        }
        if (town == "varna")
        {
            if (0 <= sales & sales <= 500)
            {
                Console.WriteLine(sales * 4.5 / 100);
            }
            else if (500 < sales & sales <= 1000)
            {
                Console.WriteLine(sales * 7.5 / 100);
            }
            else if (1000 < sales & sales <= 10000)
            {
                Console.WriteLine(sales * 10 / 100);
            }
            else if (sales > 10000)
            {
                Console.WriteLine(sales * 13 / 100);
            }
            else if (sales < 0)
            {
                Console.WriteLine("error");
            }
            else if (comission == -1.0)
            {
                Console.WriteLine("{0:f2}", sales * comission);
            }
        }
        if (town == "plovdiv")
        {
            if (0 <= sales & sales <= 500)
            {
                Console.WriteLine(sales * 5.5 / 100);
            }
            else if (500 < sales & sales <= 1000)
            {
                Console.WriteLine(sales * 8 / 100);
            }
            else if (1000 < sales & sales <= 10000)
            {
                Console.WriteLine(sales * 12 / 100);
            }
            else if (sales > 10000)
            {
                Console.WriteLine(sales * 14.5 / 100);
            }
            else if (sales < 0)
            {
                Console.WriteLine("error");
            }
            else if (comission == -1.0)
            {
                Console.WriteLine("{0:f2}", sales * comission);
            }
        }

        else
        {
            Console.WriteLine("error");
        }
    }
}