08.01 Trade Comissions

using System;
class Program
{
    static void Main()
    {
        var city = Console.ReadLine().ToLower();
        var sales = double.Parse(Console.ReadLine());
        var comission = 0.0;

        if (city == "sofia")
        {
            if (0 <= sales && sales <= 500)
            {
                comission = 0.05;
            }
            else if (500 < sales && sales <= 1000)
            {
                comission = 0.07;
            }

            else if (1000 < sales && sales <= 10000)
            {
                comission = 0.08;
            }

            else if (sales > 10000)
            {
                comission = 0.12;
            }
        }
        else if (city == "varna")
        {
            if (0 <= sales && sales <= 500)
            {
                comission = 0.045;
            }
            else if (500 < sales && sales <= 1000)
            {
                comission = 0.075;
            }

            else if (1000 < sales && sales <= 10000)
            {
                comission = 0.10;
            }

            else if (sales > 10000)
            {
                comission = 0.13;
            }
        }
        else if (city == "plovdiv")
        {
            if (0 <= sales && sales <= 500)
            {
                comission = 0.055;
            }
            else if (500 < sales && sales <= 1000)
            {
                comission = 0.08;
            }

            else if (1000 < sales && sales <= 10000)
            {
                comission = 0.12;
            }
            else if (sales > 10000)
            {
                comission = 0.145;
            }
        }
        if (comission > 0)
        {
            Console.WriteLine("{0:f2}", sales * comission);
        }
        else if (city != "sofia" && city != "varna" && city != "plovdiv" || sales < 0)
        {
            Console.WriteLine("error");
        }
    }
}