using System;

using System.Collections.Generic;

using System.Text;

using System.IO;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var list = new List<string> { "awb1", "awb2" };

        list.Sort();

        var text = string.Join(", ", list);

        Console.WriteLine( text );

        byte[] bytetext = Encoding.UTF8.GetBytes(text);

        MemoryStream textstream = new(bytetext);

        System.Security.Cryptography.HMACMD5 hmac = new(Encoding.UTF8.GetBytes("courierpin"));

        byte[] hashValue = hmac.ComputeHash(textstream);

​

        var result = Math.Abs(BitConverter.ToInt32(hashValue, 0));

​

        Console.WriteLine( result.ToString()[..4] );

    }

}