using System;

using System.Threading;

using System.Threading.Tasks;

public class Program

{

    public static async Task Main()

    {

        Console.WriteLine("Start");

        var task1 = Task1();

        var task2 = Task2();

        await Task.Delay(30);

        Console.WriteLine("Middle");

        await Task.WhenAll(task1, task2);

        Console.WriteLine("End");

    }

    public static async Task Task1()

    {

        await Task.Delay(20);

        Console.WriteLine("Task1");

    }

    public static async Task Task2()

    {

        await Task.Delay(10);

        Console.WriteLine("Task2");

    }

}