public class Time {
    private final int seconds;

    public Time(int h, int m, int s) {
        seconds = h * 3600 + m * 60 + s;
    }

    public Time(String time) {
        String[] parts = time.split(":");
        int total = 0;
        int f = 1;
        for(int i = parts.length-1; i >= 0; i--) {
            total += Integer.parseInt(parts[i])*f;
            f *= 60;
        }
        seconds = total;
    }

    public int getHours() {
        return seconds / 3600;
    }

    public int getMinutes() {
        return seconds % 3600 / 60;
    }

    public int getSeconds() {
        return seconds % 3600 % 60;
    }

    @Override
    public String toString() {
        return getHours() + ":" + getMinutes() + ":" + getSeconds();

    }

    public Time add(Time t) {
        return new Time(0, 0, seconds + t.seconds);
    }

    public static void main(String[] args) {
        Time t1 = new Time(1, 20, 5);
        Time t2 = new Time("45:0");

        System.out.println(t1);
        System.out.println(t2);
        Time t3 = t1.add(t2);
        System.out.println(t3);
    }
}