using System;

using System.Collections;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        List<int[]> x = new List<int[]>();

        x.Add(new int[]{ 1,2});

        x.Add(new int[]{ 3,4});

        var y = new List<int[]>(x);

        y[0][0] = 345;

        foreach(var i in x){

            foreach( var i2 in i)

            {

                Console.WriteLine(i2);

            }

        }

        foreach(var i in y){

            foreach( var i2 in i)

            {

                Console.WriteLine(i2);

            }

        }

    }

}