seconds -= hours / (60*60);
seconds -= hours * (60*60);
std::ostream& operator<<(std::ostream& out, const Timer& timer) {    int seconds = int(timer.seconds());    int days = seconds / (60*60*24);    seconds -= days * (60*60*24);    int hours = seconds / (60*60);    seconds -= hours / (60*60);    int minutes = seconds / 60;    seconds -= minutes * 60;    if (days > 0)	out << days << "d ";    if (hours > 0)	out << std::setw(2) << std::setfill('0') << hours << ':';    return out << std::setw(2) << std::setfill('0') << minutes << ':'	       << std::setw(2) << std::setfill('0') << seconds; }