#include <bits/stdc++.h>
using namespace std;
int main(){
	int s,v,hour,minute;
	cin >> s >> v;
	if(s%v == 0) s /= v;
	else s = s/v+1;
	s += 10;
	hour = s/60;
	minute = s%60;
	if(minute!=0) minute=60-minute;
	else{
		minute = 0;
		hour -= 1;
	}
	if (hour<8) hour = 7-hour;
	else hour = 32-hour;
	if(hour==24) hour = 0;
	printf("%02d:%02d\n",hour,minute);
	return 0;
}