// Problem: P5707 【深基2.例12】上学迟到
// Contest: Luogu
// URL: https://www.luogu.com.cn/problem/P5707
// Memory Limit: 125 MB
// Time Limit: 1000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include<bits/stdc++.h>
using namespace std;
int s,v,h,m,ansh,ansm,t;
int main()
{
	std::ios::sync_with_stdio (false);
	cin>>s>>v;
	t=s/v;
	if(s%v!=0) t+=1;
	t+=10;
	m=t%60;
	h=(t-m)/60+1;
	ansh=8-h;
	if(ansh<0) ansh=24-h+8;
	ansm=60-m;
	if(m==0) ansm=0,ansh++;
	if(ansh<10 && ansm<10) cout<<"0"<<ansh<<":"<<"0"<<ansm;
	if(ansh>10 && ansm<10) cout<<ansh<<":"<<"0"<<ansm;
	if(ansh<10 && ansm>10) cout<<"0"<<ansh<<":"<<ansm;
	if(ansh>10 && ansm>10) cout<<ansh<<":"<<ansm;
	return 0;
}