#include <bits/stdc++.h>
using namespace std;
template <class T>
using vec = vector<T>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const double PI = 3.141592653589;
const char nl = '\n';
long long binpow(long long a, long long b, long long m) {
  a %= m;
  long long res = 1;
  while (b > 0) {
    if (b & 1) res = res * a % m;
    a = a * a % m;
    b >>= 1;
  }
  return res;
}
void solve() {
  long long k;
  cin >> k;
  vector<long long> c(10, 1);
  long long ans = 1;
  long long curr = 1;
  while (ans < k) {
    curr++;
    for (long long i = 0; i < 10; i++) {
      c[i] = curr;
      ans /= curr - 1;
      ans *= curr;
      if (ans >= k) break;
    }
  }
  string second = "codeforces";
  for (long long i = 0; i < 10; i++) {
    while (c[i]--) {
      cout << second[i];
    }
  }
  cout << nl;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long no = 1;
  while (no--) {
    solve();
  }
  return 0;
}
