#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n;
  cin >> n;
  string s = "codeforces";
  long long cnt = 1, j = 0;
  vector<long long> v(10, 1);
  while (cnt < n) {
    v[j]++;
    j = (j + 1) % 10;
    cnt = 1;
    for (int i = 0; i < 10; i++) {
      cnt *= v[i];
    }
  }
  for (int i = 0; i < 10; i++) {
    while (v[i]--) {
      cout << s[i];
    }
  }
  cout << endl;
  return;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  solve();
  return 0;
}
