using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        string[] ints1 = { "x", "y" };

        string[] ints2 = { "y", "Z" };

​

        IEnumerable<string> union = ints1.Union(ints2);

​

        foreach (string num in union)

        {

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

        }

    }

}