using System;

using System.Collections;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        string[] str=new string[]{"apple","banana","apple"};

        ArrayList s=new ArrayList();

        for(int i=0;i<str.Length;i++)

        {

            Console.WriteLine(s);

        if(s.Contains(str[i]))

        {

        s.Add(s[i]);

        }

            Console.WriteLine("dd{0}",s);

        }

    }

}