#include<bits/stdc++.h>
using namespace std;
int s,v;
int minute,hour;
int main() {
	scanf("%d%d",&s,&v);
	minute = ceil(1.0 * s / v) + 10;
	minute %= 60;
	hour = ceil(1.0 * minute / 60);
	printf("%02d:%02d", (8 - hour + 24) % 24, (0 - minute + 60) % 60);
	return 0;
}