#include<iostream>
using namespace std;
typedef long long LL;
int main()
{
    LL sum ;
    cin >> sum;
    sum /= 1000;
    sum %= 86400;
    int h = sum / 3600;
    int s = sum % 60;
    int m = (sum % 3600 - s) / 60;
    printf("%02d:%02d:%02d",h,m,s);//自动补零
}