#include <bits/stdc++.h>
using namespace std;
vector<int> arr(10, 1);
long long int prod = 1, k;
void solve() {
  cin >> k;
  while (1) {
    if (prod >= k) return;
    for (int i = 0; i < 10; i++) {
      arr[i] += 1;
      prod /= arr[i] - 1;
      prod *= arr[i];
      if (prod >= k) return;
    }
  }
}
int main() {
  map<int, char> m;
  m[0] = 'c';
  m[1] = 'o';
  m[2] = 'd';
  m[3] = 'e';
  m[4] = 'f';
  m[5] = 'o';
  m[6] = 'r';
  m[7] = 'c';
  m[8] = 'e';
  m[9] = 's';
  solve();
  for (int i = 0; i < 10; i++) {
    for (int j = 0; j < arr[i]; j++) cout << m[i];
  }
}
