using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<int> ints1 = new List<int>{ 5, 3, 9, 7, 5, 9, 3, 7 };

        List<int> ints2 = new List<int> { 8, 3, 6, 4, 4, 9, 1, 0 };

​

        ints1.Sort(); 

        ints2.Sort(); 

        Console.Write("list 1 = "); 

        foreach (var num1 in ints1)

        Console.Write("{0} ", num1.ToString());

        Console.WriteLine(); 

​

        Console.Write("list 2 = "); 

        foreach (int num2 in ints2)

        Console.Write("{0} ", num2.ToString());

        Console.WriteLine(); 

​

        var union = ints1.Union(ints2);

        Console.WriteLine("Union"); 

        foreach (int num in union)

        {

            Console.Write("{0} ", num);

        }

        Console.WriteLine();

        var diff12 = ints1.Except(ints2);

        Console.WriteLine("Diff 1-2"); 

        foreach (int num in diff12)

        {

            Console.Write("{0} ", num);

        }

        Console.WriteLine();

        var diff21 = ints2.Except(ints1);

        Console.WriteLine("Diff 2-1"); 

        foreach (int num in diff21)

        {

            Console.Write("{0} ", num);

        }

        Console.WriteLine();

        var diffunion = diff12.Union(diff21);

        Console.WriteLine("Diff Union"); 

        foreach (int num in diffunion)

        {

            Console.Write("{0} ", num);

        }

        Console.WriteLine();

        var diffconcat = diff12.Concat(diff21);

        Console.WriteLine("Diff Concat"); 

        foreach (int num in diffconcat)

        {

            Console.Write("{0} ", num);

        }

    }

}

​