#include <bits/stdc++.h>
using namespace std;
void solve();
void qr() {
  int n;
  cin >> n;
  while (n--) solve();
}
long long q, n;
void solve() { return; }
bool isPerfectSquare(long double x) {
  long double sr = sqrt(x);
  return ((sr - floor(sr)) == 0);
}
long long sum(vector<long long> &times) {
  long long rs = 1;
  for (auto i : times) {
    rs *= i;
  }
  return rs;
}
int main() {
  long long n;
  cin >> n;
  string rs = "";
  string initial = "codeforces";
  int pt = 0;
  vector<long long> times(10, 1);
  if (n == 1) {
    cout << "codeforces"
         << "\n";
    ;
    return 0;
  }
  bool flag = 0;
  for (int i = 0; i < 1000000 && !flag; i++) {
    for (int j = 0; j < 10; j++) {
      times[j]++;
      long long sofar = sum(times);
      if (sofar >= n) {
        flag = 1;
        break;
      }
    }
  }
  for (int i = 0; i < 10; i++) {
    for (int j = 0; j < times[i]; j++) {
      rs += initial[i];
    }
  }
  cout << rs << "\n";
  ;
  return 0;
}
