using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        List<string> list = new List<string>();

        list.Add("test 1");

        list.Add("test 2");

        list.Add(null);

        list.Add("test 3");

        list.Add(null);

        Console.WriteLine(list.Count);

    }

}