#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n;
  cin >> n;
  string s = "codeforces";
  if (n == 1) {
    cout << s << '\n';
    return;
  }
  int val = 0;
  while (1) {
    if (pow(val, 10) <= n and pow(val + 1, 10) >= n) break;
    val++;
  }
  vector<int> v(10, val);
  for (int i = 0; i < 10; i++) {
    long long num = 1;
    for (auto j : v) num *= j;
    if (num >= n) break;
    v[i]++;
  }
  for (int i = 0; i < 10; i++) {
    for (int j = 0; j < v[i]; j++) cout << s[i];
  }
  cout << '\n';
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  while (t--) solve();
  return 0;
}
