// Time class
// Version 1.0
//
// New in this version: constant methods.

#include <iostream>
using std::cout;
using std::cin;
using std::istream;
using std::ostream;

class Time
{
public:
    void initialize() { hours = minutes = 99; }

    void read(istream & in)
    {
        in >> hours;
        in.get(); // colon
        in >> minutes;
    }

    void print(ostream & out) const
    {
        out << hours << ':';
        if (minutes < 10) out << '0';
        out << minutes;
    }

    double minus(const Time & t2) const
    {
        return (hours + minutes/60.0) -
            (t2.hours + t2.minutes/60.0);
    }

private:
    int hours;
    int minutes;
};

void println(const Time & t, ostream & out)
{
    t.print(out);
    out << '\n';
}

int main()
{
    Time t;
    t.initialize();
    println(t, cout);
    println(t, cout);

    return 0;
}