#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<cstdio>
using namespace std;

int main()
{
	int a, b, c, d,hour,Smin,min;
	double T,s,v;
	cin >> s>> v ;
	T= s/v;
	Smin = 8 * 60 - T - 10;
    hour = Smin / 60;
	min = Smin%60;
	printf("%02d: %02d", hour, min);
	return 0;
}