#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  long long prod = 1;
  int arr[10];
  for (int i = 0; i < 10; i++) arr[i] = 1;
  int p = 0;
  while (prod < n) {
    p %= 10;
    prod /= arr[p];
    ++arr[p];
    prod *= arr[p];
    p++;
  }
  string s = "codeforces";
  for (int i = 0; i < 10; i++) {
    for (int j = 0; j < arr[i]; j++) cout << s[i];
  }
  return 0;
}
