using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public class M

    {

        public int N {get;set;}

        public override string ToString()

        {

            return N.ToString();

        }

    }

​

    public static void Main()

    {

        List<M> L1 = new List<M>();

        L1.Add(new M(){N = 1});

        L1.Add(new M(){N = 2});

        L1.Add(new M(){N = 3});

        L1.Add(new M(){N = 4});

        L1.Add(new M(){N = 5});

        List<M> L2 = new List<M>();

        L2.AddRange(L1);

        L1[1].N = 9;

        L2.ForEach(Console.WriteLine);

    }

}