using System;

using System.Collections;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        List<int> intlist = new List<int>();

        intlist.Add(1);

        intlist.Add(2);

        IList il = (IList)intlist;

        object o = il[1];

        Console.WriteLine(o);

        il.Add(7);

        object o2 = il[2];

        Console.WriteLine(o2);

    }

}