#include <bits/stdc++.h>
using namespace std;
long long n, m = 1, k = 1;
long long s[20] = {0};
char c[15] = "0codeforces";
signed main() {
  cin >> n;
  for (long long i = 1; i <= 10; i++) s[i] = 1;
  while (m < n) {
    m /= s[k];
    s[k]++;
    m *= s[k];
    k++;
    if (k == 11) k = 1;
  }
  for (long long i = 1; i <= 10; i++) {
    while (s[i]--) cout << c[i];
  }
  return 0;
}
