#include<bits/stdc++.h>
using namespace std;
int main(){
    int x;
    cin >> x;
    x /= 1000;
    int a = x % (24*3600) / 3600;
    int b = x % 3600 / 60;
    int c = x %60;
    printf("%02d:%02d:%02d",a,b,c);
}