using System;

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

            double commissions = 0.0;
            if (town == "Sofia")
            {
                if (sales >= 0 && sales <= 500)
                {
                    commissions = 5;
                    Console.WriteLine($"{sales * commissions/100:F2}");
                }
                else if (sales > 500 && sales <= 1000)
                {
                    commissions = 7;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales > 1000 && sales <= 10000 )
                {
                    commissions = 8;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales > 10000)
                {
                    commissions = 12;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales < 0)
                {
                    Console.WriteLine("error");
                }
                else if (commissions == -1.0)
                {
                    commissions = -1.0;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
            }
            if (town == "Varna")
            {
                if (sales >= 0 && sales <= 500)
                {
                    commissions = 4.5;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales > 500 && sales <= 1000)
                {
                    commissions = 7.5;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales > 1000 && sales <= 10000)
                {
                    commissions = 10;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales > 10000)
                {
                    commissions = 13;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales < 0)
                {
                    Console.WriteLine("error");
                }
                else if (commissions == - 1.0)
                {
                    commissions = -1.0;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
            }
            if (town == "Plovdiv")
            {
                if (sales >= 0 && sales <= 500)
                {
                    commissions = 5.5;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales > 500 && sales <= 1000)
                {
                    commissions = 8;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales > 1000 && sales <= 10000)
                {
                    commissions = 12;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales > 10000)
                {
                    commissions = 14.5;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
                else if (sales < 0)
                {
                    Console.WriteLine("error");
                }
                else if (commissions == -1.0)
                {
                    commissions = -1.0;
                    Console.WriteLine($"{sales * commissions / 100:F2}");
                }
            }
            else
            {
                Console.WriteLine("error");
            }
        }
    }
}