```cpp
#include<bits/stdc++.h>
using namespace std ;
int u , m , h=8 , k=0 ;
int main() {
cin >> u >> m ;
k = k-(u+m-1)/m-10 ;
h = h-(abs(k)+59)/60 ;
if(h<0) h = 24-abs(h) ;
k = 60-abs(k)%60 ;
if(h<10) cout << 0 ;
cout << h << ":" ;
if(k<10) cout << 0 ;
cout << k ;
return 0 ;
}
```
by lao_wang @ 2023-09-06 14:22:32