using System;

public class Program

{

    public static void Main()

    {

        var x = new byte[] { 99, 108, 111, 115, 101, 13, 10, 13, 10, 204, 159, 67, 4 };

        var z = System.Text.Encoding.UTF8.GetString(x);

        Console.WriteLine(z);

        Console.WriteLine();

        var idx = z.IndexOf("\r\n\r\n");

        Console.WriteLine("index = " + idx);

        Console.WriteLine("=========================");

        var x1 = new byte[] { 99, 108, 111, 115, 101, 13, 10, 13, 10, 5, 159, 67, 4 };

        var z1 = System.Text.Encoding.UTF8.GetString(x1);

        Console.WriteLine(z1);

        Console.WriteLine();

        var idx1 = z1.IndexOf("\r\n\r\n");

        Console.WriteLine("index modified = " + idx1);

        Console.WriteLine("=========================");

        var x2 = new byte[] { 13, 10, 13, 10, 204, 159 };

        var z2 = System.Text.Encoding.UTF8.GetString(x2);

        Console.WriteLine(z2);

        Console.WriteLine();

        var idx2 = z2.IndexOf("\r\n\r\n");

        Console.WriteLine("index short = " + idx2);

    }

}