using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string[] listA = {"one","two","three","one","two","three","one","two","three"};

        string[] listB = {"one","two","one","two"};

        string[] listC = listA.Intersect(listB).ToArray();

        foreach (string item in listC)

            Console.WriteLine(item);

    }

}