using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _08.TradeComission
{
    class Program
    {
        static void Main(string[] args)
        {
            var town = Console.ReadLine().ToLower();
            var sales = double.Parse(Console.ReadLine());
            var comission = 0.0;

            if (town=="sofia")
            {
                if (sales > 10000) comission = 12.00;
                else if (sales > 1000) comission = 8.00;
                else if (sales > 500) comission = 7.00;
                else if (sales > 0) comission = 5.00;

            }

           else if (town == "varna")
            {
                if (sales > 10000) comission = 13.00;
                else if (sales > 1000) comission = 10.00;
                else if (sales > 500) comission = 7.50;
                else if (sales > 0) comission = 4.50;

            }
            else if (town == "plovdiv")
            {
                if (sales > 10000) comission = 14.50;
                else if (sales > 1000) comission = 12.00;
                else if (sales > 500) comission = 8.00;
                else if (sales > 0) comission = 5.50;

            }
            if (town!="sofia"&&town!="varna"&&town!="plovdiv"||!(sales>0))
            {
                Console.WriteLine("error");

            }
            else Console.WriteLine("{0:f2}",sales * comission / 100);


        }
    }
}