#include <bits/stdc++.h>
using namespace std;
long long log_10(long long x) {
  long long pwr = 1;
  if (x < 10) return 0;
  for (int i = 0; i < 18; i++) {
    pwr *= 10;
    if (pwr > x) {
      return i;
    }
  }
  return -1;
}
int main() {
  long long n;
  cin >> n;
  if (n == 1) {
    cout << "codeforces" << endl;
    return 0;
  }
  double d = pow(1.0 * n, 0.1);
  int p = d;
  long long myMin = 10000000;
  for (long long A = p; A < p + 2; A++) {
    for (long long B = p; B < p + 2; B++) {
      for (long long C = p; C < p + 2; C++) {
        for (long long D = p; D < p + 2; D++) {
          for (long long E = p; E < p + 2; E++) {
            for (long long F = p; F < p + 2; F++) {
              for (long long G = p; G < p + 2; G++) {
                for (long long H = p; H < p + 2; H++) {
                  for (long long I = p; I < p + 2; I++) {
                    for (long long J = p; J < p + 2; J++) {
                      if (A * B * C * D * E * F * G * H * I * J >= n) {
                        myMin =
                            min(A + B + C + D + E + F + G + H + I + J, myMin);
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  string s = "codeforces";
  long long x = myMin / 10;
  for (int i = 0; i < myMin % 10; i++) {
    for (int j = 0; j < x + 1; j++) {
      cout << s[i];
    }
  }
  for (int i = myMin % 10; i < 10; i++) {
    for (int j = 0; j < x; j++) {
      cout << s[i];
    }
  }
}
