#include <iostream>
#include<cmath>
using namespace std;
int main()
{
	int s, v, x = 0, shijian = 0, xiaoshi = 0, fengzhong = 0;
	cin >> s >> v;
	x = ceil(1.0 * s / v) + 10;
	shijian = 60 * 32 - x;
	xiaoshi = (shijian / 60) % 24;
	fengzhong = shijian % 60;
	if (xiaoshi < 10)
	{
		cout << "0" << xiaoshi << ":" << fengzhong;
		if (fengzhong < 10)
			cout << "0" << xiaoshi << ":0" << fengzhong;
	}
	else
	{
		cout << xiaoshi << ":" << fengzhong;
		if (fengzhong < 10)
		{
			cout << xiaoshi << ":0" << fengzhong;
		}
	}
	return 0;
}