Просвещайтесь https://ru.wikipedia.org/wiki/%D0%A1%D0%BF%D0%B8%D1%81%D0%BE%D0%BA_%D1%86%D0%B5%D1%80%D0%BA%D0%B2%D0%B5%D0%B9_%D0%A1%D1%82%D0%B0%D0%BC%D0%B1%D1%83%D0%BB%D0%B0