using System;

namespace _09.TradeCommissions
{
    class Program
    {
        static void Main(string[] args)
        {
            string town = Console.ReadLine();
            double volumeOfSales = double.Parse(Console.ReadLine());

            double commission = 0;
            if (0 > volumeOfSales)
            {
                Console.WriteLine("error");
            }
            else if (town == "Sofia")
            {
                if (0 <= volumeOfSales && volumeOfSales <= 500)
                {
                    commission = volumeOfSales * 0.05;
                }
                else if (500 < volumeOfSales && volumeOfSales <= 1000)
                {
                    commission = volumeOfSales * 0.07;
                }
                else if (1000 < volumeOfSales && volumeOfSales <= 10000)
                {
                    commission = volumeOfSales * 0.08;
                }
                else if (volumeOfSales > 10000)
                {
                    commission = volumeOfSales * 0.12;
                }

                Console.WriteLine($"{commission:F2}");
            }
            else if (0 > volumeOfSales)
            {
                Console.WriteLine("error");
            }
            else if (town == "Varna")
            {
                if (0 <= volumeOfSales && volumeOfSales <= 500)
                {
                    commission = volumeOfSales * 0.045;
                }
                else if (500 < volumeOfSales && volumeOfSales <= 1000)
                {
                    commission = volumeOfSales * 0.075;
                }
                else if (1000 < volumeOfSales && volumeOfSales <= 10000)
                {
                    commission = volumeOfSales * 0.1;
                }
                else if (volumeOfSales > 10000)
                {
                    commission = volumeOfSales * 0.13;
                }

                Console.WriteLine($"{commission:F2}");
            }
            else if (town == "Plovdiv")
            {
                if (0 <= volumeOfSales && volumeOfSales <= 500)
                {
                    commission = volumeOfSales * 0.055;
                }
                else if (500 < volumeOfSales && volumeOfSales <= 1000)
                {
                    commission = volumeOfSales * 0.08;
                }
                else if (1000 < volumeOfSales && volumeOfSales <= 10000)
                {
                    commission = volumeOfSales * 0.12;
                }
                else if (volumeOfSales > 10000)
                {
                    commission = volumeOfSales * 0.145;
                }

                Console.WriteLine($"{commission:F2}");

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



        }
    }
}