# include <iostream>
using namespace std;

class Time
{
	private:
		int hour,minute,second;
	public:
		Time();
		Time(int h);
		Time(int h,int m,int s);
		void printTime();
		void print12();
};

void	Time::print12()
{
	if(hour>12) 
		cout<<(hour-12)<<":"<<minute<<":"<<second<<endl;
	else
		printTime();
}

Time::Time()
{
	hour=0;
	minute=0;
	second=0;
}

Time::Time(int h)
{
	hour=h;
	minute=0;
	second=0;
}

Time::Time(int h,int m,int s)
{
	hour=h;
	minute=m;
	second=s;
}

void	Time::printTime()
{
	cout<<hour<<":"<<minute<<":"<<second<<endl;
}

int main()
{
	Time t1;
	Time t2(12);
	Time t3(20,15,20);
	t1.print12();
	t2.print12();
	t3.print12();
	return 0;
}