using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var ints = new List<int?>

        {

            null,

            null,

            3,

            null,

            6

        };

        Console.WriteLine("No ordering:");

        foreach(var i in ints)

        {

            Console.WriteLine(i.HasValue ? i.ToString() : "NULL");

        }

        Console.WriteLine();

        Console.WriteLine("Ordering:");

        foreach(var i in ints.OrderBy(oi => oi))

        {

            Console.WriteLine(i.HasValue ? i.ToString() : "NULL");

        }

        Console.WriteLine();

        Console.WriteLine("Null modified ordering:");

        foreach(var i in ints.OrderBy(oi => oi ?? int.MaxValue))

        {

            Console.WriteLine(i.HasValue ? i.ToString() : "NULL");

        }

    }

}