#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long int k;
  cin >> k;
  string s = "codeforces";
  long long int a[10];
  long long int cnt = 1;
  for (int i = 0; i < 10; ++i) {
    a[i] = 1;
  }
  int idx = 0;
  while (cnt < k) {
    a[idx]++;
    cnt = 1;
    for (int i = 0; i < 10; ++i) {
      cnt *= a[i];
    }
    idx = (idx + 1) % 10;
  }
  for (int i = 0; i < 10; ++i) {
    for (int j = 0; j < a[i]; ++j) {
      cout << s[i];
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
