using System;

using System.Collections;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        int[] first = {3, 4, 5, 6};

        int[] second  = {5, 6, 8, 20};

        /*ArrayList results = new ArrayList();

        for (int x = 0; x < first.GetLength(0); x++)

        {

            results.Add(first[x] * second[x]);

            Console.WriteLine(results[x]);

        }

        */

            ArrayList newlist = new ArrayList();

            newlist.Add(first.Select(x => x * x));

            int [] newlistarray = newlist.Cast<int>().ToArray();

        /*

            for (int y = 0; (y < newlistarray.GetLength(0)); y++)

            {

                Console.WriteLine(newlistarray[y]);

            }

        */

            Console.WriteLine(newlistarray[1]);

    }

}