Вот ВАм пирамидка. Классика, однако.https://ru.wikipedia.or/wiki/%D0%9F%D0%B8%D1%80%D0%B0%D0%BC%D0%B8%D0%B4%D0%B0_%D0%BF%D0%BE%D1%82%D1%80%D0%B5%D0%B1%D0%BD%D0%BE%D1%81%D1%82%D0%B5%D0%B9_%D0%BF%D0%BE_%D0%9C%D0%B0%D1%81%D0%BB%D0%BE%D1%83