using System;

public class Program

{

    public static void Main()

    {

        var input = "008aaa69-6f65-4411-9047-a8c700a5a219 ";

        var newID = Encode(new Guid(input));

        Console.WriteLine(newID);

    }

    private static string Encode(Guid guid)

    {

        string encoded = Convert.ToBase64String(guid.ToByteArray());

        encoded = encoded

            .Replace("/", "_")

            .Replace("+", "-");

        return encoded.Substring(0, 22);

    }

}