using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var x = new [] {1, 1, 2, 3, 4};

        var y = new [] {1, 5, 2, 5, 1};

        foreach(var i in x.Union(y))

        {

            Console.WriteLine(i);

        }

    }

}