Union two HashSet in CSharp

/* w  w w.j a va 2 s.  c om*/
using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        HashSet<int> evenNumbers = new HashSet<int>();
        HashSet<int> oddNumbers = new HashSet<int>();

        for (int i = 0; i < 5; i++)
        {
            evenNumbers.Add(i * 2);
            oddNumbers.Add((i * 2) + 1);
        }
        HashSet<int> numbers = new HashSet<int>(evenNumbers);
        numbers.UnionWith(oddNumbers);

        foreach (int i in numbers)
        {
            Console.WriteLine(i);
        }
    }
}