using System;

using System.Collections;

using System.Threading.Tasks;

using System.Collections.Generic;

public class Program

{

    public static async Task Main()

    {

        var numTasks = 1;

        List<Task> tasks = new List<Task>();

        for (int i = 0; i < numTasks; i++)

        {

            Task task = Task.Run(async () =>

            {

                await Task.Delay(TimeSpan.FromSeconds(10));

            });

            tasks.Add(task);

        }

        await Task.WhenAll(tasks);

​

        Console.WriteLine("Hello World");

    }

}