#include <bits/stdc++.h>
using namespace std;
double pi = 2 * acos(0.0);
long long int power(long long int a, long long int b) {
  long long int res = 1;
  while (b) {
    if (b & 1) res = res * a;
    b = b / 2;
    a = (a * a);
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long int tst;
  tst = 1;
  while (tst--) {
    bool flag = true;
    long long anscnt = 0, ansnum = 0;
    unsigned long long n;
    cin >> n;
    for (int i = 1; i <= 40; i++) {
      for (int j = 0; j <= 10; j++) {
        if ((power(i, 10 - j) * power(i + 1, j)) >= n) {
          anscnt = i;
          ansnum = 10 - j;
          flag = false;
          break;
        }
      }
      if (flag == false) break;
    }
    string str = "codeforces";
    string ans = "";
    for (int i = 0; i < ansnum; i++) {
      for (int j = 1; j <= anscnt; j++) {
        ans += str[i];
      }
    }
    anscnt++;
    for (int i = ansnum; i <= 9; i++) {
      for (int j = 1; j <= anscnt; j++) {
        ans += str[i];
      }
    }
    cout << ans;
  }
}
