签到题，没啥好说的

#include <iostream>
#include <algorithm>
#include <cstring>

using namespace std;

typedef long long LL;

LL thetime;
LL mod = 24 * 60 * 60 * 1000;
LL newtime;
int hh, mm, ss;

int main()
{
    cin >> thetime;
    newtime = thetime % mod / 1000;

    hh = newtime / 3600;
    mm = newtime % 3600 / 60;
    ss = newtime % 60;

    printf("%02d:%02d:%02d\n", hh, mm, ss);

    return 0;
}