07. Trade Commissions

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

        if (town == "sofia")
        {
            if (sales >= 0 && sales <= 500)
            {
                commission = 0.05;
            }
            else if (sales <= 1000)
            {
                commission = 0.07;
            }
            else if ( sales <= 10000)
            {
                commission = 0.08;
            }
            else if (sales > 10000)
            {
                commission = 0.12;
            }
        }
        if (town == "varna")
        {
            if (sales >= 0 && sales <= 500)
            {
                commission = 0.045;
            }
            else if (  sales <= 1000)
            {
                commission = 0.075;
            }
            else if ( sales <= 10000)
            {
                commission = 0.1;
            }
            else if (sales > 10000)
            {
                commission = 0.13;
            }
        }
        if (town == "plovdiv")
        {
            if (sales >= 0 && sales <= 500)
            {
                commission = 0.055;
            }
            else if (sales>500 &&sales <= 1000)
            {
                commission = 0.08;
            }
            else if (sales>1000&& sales<= 10000)
            {
                commission = 0.12;
            }
            else if (sales > 10000)
            {
                commission = 0.145;
            }

        }
        if (commission >= 0)
        {
            Console.WriteLine("{0:f2}", commission * sales);
        }
        else
        {
            Console.WriteLine("error");
        }

    }

}