using System;

namespace TradeCommissions
{
    class Program
    {
        static void Main(string[] args)
        {
            string town = Console.ReadLine();
            double seels = double.Parse(Console.ReadLine());
            double dicount = 0;
            bool isValid = true;


            switch (town)
            {
                case "Sofia":
                    if (0 <= seels && seels <= 500)
                    {
                        dicount = seels * 0.05;
                    }
                    else if (500 < seels && seels <= 1000)
                    {
                        dicount = seels * 0.07;
                    }
                    else if (1000 < seels && seels <= 10000)
                    {
                        dicount = seels * 0.08;
                    }
                    else if (seels > 10000)
                    {
                        dicount = seels * 0.12;
                    }
                    else if (seels < 0)
                    {
                        isValid = false;
                    }
                    break;

                case "Varna":
                    if (0 <= seels && seels <= 500)
                    {
                        dicount = seels * 0.045;
                    }
                    else if (500 < seels && seels <= 1000)
                    {
                        dicount = seels * 0.075;
                    }
                    else if (1000 < seels && seels <= 10000)
                    {
                        dicount = seels * 0.10;
                    }
                    else if (seels > 10000)
                    {
                        dicount = seels * 0.13;
                    }
                    else if (seels < 0)
                    {
                        isValid = false;
                    }
                    break;

                case "Plovdiv":
                    if (0 <= seels && seels <= 500)
                    {
                        dicount = seels * 0.055;
                    }
                    else if (500 < seels && seels <= 1000)
                    {
                        dicount = seels * 0.08;
                    }
                    else if (1000 < seels && seels <= 10000)
                    {
                        dicount = seels * 0.12;
                    }
                    else if (seels > 10000)
                    {
                        dicount = seels * 0.145;
                    }
                    else if (seels < 0)
                    {
                        isValid = false;
                    }
                    break;

                default:
                    isValid = false;
                    break;

            }

            if (isValid)
            {
                Console.WriteLine($"{dicount:f2}");
            }
            else
            {
                Console.WriteLine("error");
            }

        }
    }
}