using System;

public class Program

{

    public static void Main()

    {

        string str = "C221";

        char? foo = GetFirmTypeFromFirmID(str);

        var goo =  GetFirmIDFromFirmID(foo, str);

        Console.WriteLine(foo);

        Console.WriteLine(goo);

    }

    private static char? GetFirmTypeFromFirmID(string firmID)

        {

            char? firmType = null;

​

            if(firmID != null && firmID != ""){

                firmType = firmID[0];

            }

​

            return firmType;

        }

    private static string GetFirmIDFromFirmID(char? splitChar, string firmID)

        {

            string MRMFirmID = null;

​

            if (splitChar.HasValue){

                try

                {

                    string[] firmIDStrArr = firmID.Split(splitChar.Value);

​

                    if (firmIDStrArr.Length > 0)

                    {

                        MRMFirmID = firmID.Split(splitChar.Value)[1];

                    }

                }

                catch (Exception e)

                {

                    Console.WriteLine(e.Message);

                }

            }

​

            return MRMFirmID;

        }

}