#include <bits/stdc++.h>
using namespace std;
const long long maxn = 2e5 + 5;
const long long inf = 9e18;
const double pi = acos(-1);
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie();
  cout.tie();
  long long k;
  cin >> k;
  string s = "codeforces";
  map<long long, long long> cnt;
  for (long long i = 0; i < s.length(); i++) {
    cnt[i] = 1;
  }
  long long cur = 1;
  bool flag = false;
  while (true) {
    long long cur = 1;
    if (cur >= k) {
      break;
    }
    for (long long i = 0; i < s.length(); i++) {
      cnt[i]++;
      for (long long i = 0; i < s.length(); i++) {
        cur *= cnt[i];
      }
      if (cur >= k) {
        flag = 1;
        break;
      }
      cur = 1;
    }
    if (flag) break;
  }
  for (long long i = 0; i < s.length(); i++) {
    for (long long j = 0; j < cnt[i]; j++) cout << s[i];
  }
  cout << endl;
  return 0;
}
