using System;

using System.Text;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Console.WriteLine(GetPrefixFromName("AB1234"));

        Console.WriteLine(GetPrefixFromName("ab1234"));

        Console.WriteLine(GetPrefixFromName("aVbC1234"));

        Console.WriteLine(GetPrefixFromName("12DG1234"));

        Console.WriteLine(GetPrefixFromName("ABC1234"));

        Console.WriteLine(GetPrefixFromName("3331234"));

        Console.WriteLine(GetPrefixFromName("HAA00175"));

        Console.WriteLine(GetPrefixFromName("TSA00005"));

        Console.WriteLine(GetPrefixFromName("Cust name - TSX AUTO STYLING"));

​

    }

        private static string GetPrefixFromName(string customerName)

        {

            string numberPrefix = "";

​

            int nameLength = customerName.Trim().Length;

            if (nameLength > 1)

            {

                int i;

                for (i = 0; i <= nameLength - 1; i++)

                {

                    string letter = customerName.Substring(i, 1);

​

                    if (!(Encoding.Default.GetBytes(letter)[0] < 65 | (Encoding.Default.GetBytes(letter)[0]) > 90))

                    {

                        if (numberPrefix.Trim().Length == 2)

                        {

                            break;

                        }

                        else

                        {

                            numberPrefix = numberPrefix.Trim() + letter.Trim();

                        }

                    }

                }

            }

            return numberPrefix;

        }

}