using System;

using System.Runtime.InteropServices;

using System.Buffers.Binary;

​

public class Program

{

    public static void Main()

    {

        byte b = 0xFA;

        byte[] cipher = [b, b];

        int cipherInt = MemoryMarshal.Read<ushort>(cipher);

        Console.WriteLine(cipherInt);

        int reversedEndianess = BinaryPrimitives.ReverseEndianness(cipherInt);

        Console.WriteLine(reversedEndianess);

        Console.WriteLine(reversedEndianess % 0x0a0a);

    }

}