```cpp
#include <cstdio>
#include <cmath>
int main() {
int s, v;
scanf("%d%d", &s, &v);
int f = 60 * (24 + 8) - (10 + ceil(double(s) / v));
int h = (f / 60) % 24;
int m = f % 60;
printf("%02d:%02d", h, m);
}
```
by CarrotMeow @ 2023-10-10 16:11:37