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

using namespace std;

typedef long long  LL;

int main()
{
    LL n; 
    cin >> n;
    n = n / 1000 % 86400;
    int h = n / 3600;
    n %= 3600;
    int m = n / 60;
    int s = n % 60;
    printf ("%02d:%02d:%02d\n", h, m, s);

    return 0;
}