#include <bits/stdc++.h>
using namespace std;
long long a[15];
long long ans = 1, x;
void solve(long long k) {
  while (ans < k) {
    a[x] += 1;
    x = (x + 1) % 10;
    ans = 1;
    for (int i = 0; i < 10; i++) ans *= a[i];
  }
}
int main() {
  long long n;
  cin >> n;
  string second = "codeforces";
  for (int i = 0; i < 15; i++) a[i] = 1;
  solve(n);
  for (int i = 0; i < second.length(); i++) {
    for (int j = 0; j < a[i]; j++) {
      cout << second[i];
    }
  }
}
