```cpp
#include<bits/stdc++.h>
using namespace std;
int s,v,t;
int main(){
cin>>s>>v;
t=ceil(s*1.0/v)+10;
t=32*60-t;
if(t<=24*60){
printf("%.2d:%.2d",t/60,t%60);
}else{
printf("%.2d:%.2d",t/60-24,t%60);
}
return 0;
}
```
by small_lemon_qwq @ 2023-11-07 13:40:18