#include<bits/stdc++.h>
using namespace std;
int main(){
	int s,v,t,h,m,e,f;
	cin>>s>>v;
	t=s/v+11;
	h=t/60;
	m=t%60;
	e=7-h;
	f=60-m;
	if (e<0){
		e=24+e;
	}
	printf("%02d",e);
	cout<<":";
	printf("%02d",f);
	return 0;
}