using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var list = new List<int>();

        Console.WriteLine(list.Count);

        Foo(list);

        Console.WriteLine(list.Count);

    }

    private static void Foo(List<int> list)

    {

        list = new List<int> {1, 2, 3};

    }

}