using System;
using System.Diagnostics;

public static class Boot
{
    private static readonly Stopwatch _sw = Stopwatch.StartNew();
    private static long _last;

    public static void Mark(string what)
    {
        long now = _sw.ElapsedMilliseconds;
        Console.WriteLine("[boot] " + now.ToString().PadLeft(6) + " ms  (+" + (now - _last) + ")  " + what);
        _last = now;
    }
}