这类题通法；求余或整除，再简写运算

include [HTML_REMOVED]

using namespace std;

int main()
{
int N;
cin >> N;

int hours = N / 3600;
N %= 3600;
int minutes = N / 60;
N %= 60;
int seconds = N;

printf("%d:%d:%d\n", hours, minutes, seconds);
return 0;

}