using System;

using System.Diagnostics;

using System.Text;

using System.Threading;

public class Program

{

    public static void Main()

    {

        var stopwatch = new Stopwatch();

        var messages = new StringBuilder();

        stopwatch.Start();

        Thread.Sleep(500);

        messages.AppendLine($"Did something after {stopwatch.Elapsed}");

        Thread.Sleep(250);

        messages.AppendLine($"Did something else after {stopwatch.Elapsed}");

        Console.WriteLine(messages.ToString());

    }

}