using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
public class Program
{
public static void Main()
Console.WriteLine("Hello World");
List<string> test = new List<string>();
test.Add("hello");
test.Add("how");
test.Add("are");
test.Add("you");
string concated = String.Join(", ", test);
Console.WriteLine(concated);
}