#include <bits/stdc++.h>
using namespace std;
const int MAXN = 70, MAXM = 100, MOD = 1e9 + 7, INF = 1e9;
char c[] = {'c', 'o', 'd', 'e', 'f', 'o', 'r', 'c', 'e', 's'};
void solve() {
  long long n;
  cin >> n;
  long long x = 0, x1 = 0;
  while (pow(x + 1, 10) <= n) x++;
  while (pow(x, 10 - x1) * pow(x + 1, x1) < n) x1++;
  for (int i = 0; i < 10; i++) {
    if (i < x1)
      for (int j = 0; j <= x; j++) cout << c[i];
    else
      for (int j = 0; j < x; j++) cout << c[i];
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
}
