#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, num = 1, mul;
  cin >> n;
  string s = "codeforces";
  int ln = s.length(), a[12] = {0};
  for (long long int i = 2; i <= 100; i++) {
    long long int curr = pow(i, 10ll);
    if (curr >= n) {
      for (int j = 0; j < 10; j++) {
        a[j] = i - 1;
        num *= (i - 1);
      }
      mul = i;
      break;
    }
  }
  int pos = 0;
  while (num < n) {
    num /= (mul - 1);
    num *= mul;
    a[pos] = mul;
    pos++;
  }
  for (int i = 0; i < 10; i++) {
    for (int j = 0; j < a[i]; j++) cout << s[i];
  }
  cout << endl;
  return 0;
}
