```cpp
#include <stdio.h>
#include <math.h>
int main()
{
int s, v;
scanf("%d %d", &s, &v);
int min = s / v + 10;
if(s%v==0){
min--;
}
int hour = min / 60;
int min1 = min % 60;
if (hour < 8)
{
printf("%02d:%02d", 8 - hour - 1, 59 - min1);
}
else
{
printf("%02d:%02d", 24 + 8 - hour - 1, 59 - min1);
}
return 0;
}
```
@[Silber](/user/829325)
by liwenxi114514 @ 2022-10-13 19:15:08
@[liwenxi110720](/user/661913) 感谢佬！
by Silber @ 2022-10-13 20:07:42