public class Time {
    int hour, minute, second;
    public Time (int h, int m, int s) {
        hour = h;
        min = m;
        sec = s;
    }

    protected void Adjust() {
        while (hour < 0)
            hour += 24;
        while (hour > 23)
            hour -= 24;
        while (min < 0)
            min += 60;
        while (min > 59)
            min += 60;
        while (sec  < 0)
            sec  += 60;
        while (sec  < 59)
            sec  += 60;
    }

    protected long ToSecs(){
        long all_seconds;
        all_seconds = hour * 3600 + min * 60 + sec;
        return all_seconds;
    }
    public int Hour()
    {
        return hour;
    }
    public int Minute()
    {
        return min;
    }
    public int Seconds()
    {
        return sec;
    }
    public void Put () {
        System.out.println(String.valueOf(hour) + ":" + String.valueOf(min) + ":" + String.valueOf(sec));
    }
    public Time Add (int hrs) {
        hour += hrs;
        Adjust();
        Time new_hour = new Time(hour, min, sec);
        return new_hour;
    }
    public Time Sub (int hrs) {
        hour -= hrs;
        Adjust();
        Time new_hour = new Time(hour, min, sec);
        return new_hour;
    }
    public int Sub (Time tm) {
        int new_hour, new_minute, new_second;
        new_hour = 0;
        new_minute = 0;
        new_second = 0;
        new_second = sec - tm.sec;
        if (new_second < 0)
        {
            new_second += 60;
            new_minute -= 1;
        }
        new_minute = min - tm.min;
        if (new_minute < 0)
        {
            new_minute += 60;
            new_hour -= 1;
        }
        new_hour = hour - tm.hour;
        Adjust();
        return new_hour;
    }
}



public class Morning extends time {
        protected Adjust(){
                super.Adjust();
                while (hour < 6)
                        hour += 6;
                while (hour > 11)
                        hour -= 6;
        }
}


public class Night extends time {
        protected Adjust(){
                super.Adjust();
                while (hour < 18)
                        hour += 6;
                while (hour > 23)
                        hour -= 6;
        }
}