#include <bits/stdc++.h>
using namespace std;
struct fast {
  fast() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
  }
} cincout;
long long getCurrent(vector<long long> v) {
  long long ret = 1;
  for (long long t : v) ret *= t;
  return ret;
}
int main() {
  long long k;
  cin >> k;
  vector<long long> v(10, 1);
  while (getCurrent(v) < k) {
    for (long long &i : v) {
      i++;
      if (getCurrent(v) >= k) break;
    }
  }
  string s = "codeforces";
  string res;
  for (int i = 0; i < s.size(); i++) {
    while (v[i]--) res += s[i];
  }
  cout << res << "\n";
  return 0;
}
