```cpp
#include<bits/stdc++.h>
#define int long long
using namespace std;
double s,v;
int h=8,m=0;
signed main(){
cin>>s>>v;
int t=ceil(s/v*1.0)+10;
int a=t/60,b=t%60;
if(b!=0) h--,m=60-b;
if(a>h) a-=h,h=24-a;
else h-=a;
cout<<h/10<<h%10<<':'<<m/10<<m%10;
return 0;
}
```
by zhaojianchao @ 2023-08-24 16:06:04
@[AlgorithmArtist](/user/1044048) 你先看一下我的
by zhaojianchao @ 2023-08-24 16:06:34