using System;

public class Program

{

    public static void Main()

    { 

        ulong v = 0;

        uint h = 0xaabbccdd;

        uint l = 0xeeff;

        v = ((uint) (h << 32);

        //v = (ulong)((v << 32) |(ulong)l);

        //v |= l;

        Console.WriteLine(v);

        Console.WriteLine(v.ToString("X16"));

    }

}