#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long int k;
  cin >> k;
  string s = "codeforces";
  long long int n = s.length();
  long long int cnt[n];
  for (__typeof(n) i = (0) - ((0) > (n)); i != (n) - ((0) > (n));
       i += 1 - 2 * ((0) > (n))) {
    cnt[i] = 1;
  }
  long long int ans = 1;
  while (ans < k) {
    long long int i = 0;
    while (ans < k and i < n) {
      ans /= cnt[i];
      cnt[i]++;
      ans *= cnt[i];
      i++;
    }
  }
  for (long long int i = 0; i < n; i++) {
    for (long long int j = 0; j < cnt[i]; j++) {
      cout << s[i];
    }
  }
  cout << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t;
  t = 1;
  while (t--) {
    solve();
  }
}
