#include <bits/stdc++.h>
using namespace std;

int main() {
  int a;
  cin >> a;
  if ((a / 5 * 3) % 60 < 10) {
    cout << 10 + (a / 5 * 3) / 60 << ":0" << (a / 5 * 3) % 60 << endl;
  }
  else {
    cout << 10 + (a / 5 * 3) / 60 << ":" << (a / 5 * 3) % 60 << endl;
  }
  return 0;
}