using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

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

        List<int> l1 = new List<int>();

        l.Add(10);

        l.Add(20);

        l1 = new List<int> (l.ToArray());

        l.Add(30);

        l[0] = 0;

        Console.WriteLine(l[0]);

        Console.WriteLine(l1[0]);

        Console.WriteLine(l.ToArray().Length);

        Console.WriteLine(l1.ToArray().Length);

    }

}