using System;

using System.Threading.Tasks;

​

public class Program

{

    public static void Main()

    {

        DateTime startTime = DateTime.UtcNow;

        MainAsync().GetAwaiter().GetResult();

        TimeSpan executionTime = DateTime.UtcNow - startTime;

        Console.WriteLine("Execution took " + executionTime.TotalSeconds);

    }

​

    private static async Task MainAsync()

    {

        for (int i = 0; i < 5; i++)

        {

            await DoWork(i * 100);

        }

    }

​

    private static Task DoWork(int delayInMs)

    {

        return Task.Delay(delayInMs);

    }

}