using System;

using System.Collections.Generic;

public class Program

{

    public static void Bla(List<int> bla) {

        bla.Add(5); 

    }

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var bla = new List<int>();

        bla.Add(0);

        Bla(bla);

        foreach (var i in bla) {

        Console.WriteLine(i);   

        }

    }

}