#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const long long INF = 1e18;
const long long MAX = 100001;
void solve() {
  string test = "codeforces";
  int n = 10;
  long long k;
  cin >> k;
  vector<long long> vec(n, 1);
  long long product = 1;
  for (int i = 0; product < k; i = (i + 1) % n) {
    product = product / vec[i] * (vec[i] + 1);
    ++vec[i];
  }
  int idx = 0;
  for (long long i : vec) {
    for (int j = 0; j < i; j++) cout << test[idx];
    ++idx;
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long t;
  t = 1;
  for (int i = 1; i <= t; i++) {
    solve();
  }
  return 0;
}
