#include <bits/stdc++.h>
using namespace std;

int s,v,t,h,m;

int main () {
	scanf("%d%d",&s,&v);
	t=s/v+10;
	h=t/60,m=t%60;
	if(h>8)
		h=32-h;
	else
		h=7-h;
	m=59-m;
	if(h<10)
		printf("0%d:",h);
	else
		printf("%d:",h);
	if(m<10)
		printf("0%d",m);
	else
		printf("%d",m);
	return 0;
}

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