#include<stdio.h>
int main()
{
int start, start1, start2, end, end1, end2, p1, p2;
scanf("%d%d", &start, &end);
start1 = start / 100;
start2 = start % 100;
end1 = end / 100;
end2 = end % 100;
p1 = end1 - start1;
p2 = end2 - start2;
if (p2 < 0)
p1--, p2 += 60;
printf("%02d:%02d", p1, p2);
return 0;
}```
```