#include <bits/stdc++.h>
using namespace std;
bool solve(long long x, long long n, long long z) {
  if (x >= n) return true;
  long long y = x;
  for (long long i = 1; i < z; i++) {
    x *= y;
    if (x >= n) return true;
  }
  return false;
}
long long pw(long long a, long long b) {
  if (a < 2) return a;
  if (b == 0) return 1;
  if (b == 1) return a;
  long long p = pw(a * a, b / 2);
  if (b % 2 == 0) return p;
  return a * p;
}
int main() {
  long long n;
  cin >> n;
  string s;
  vector<long long> v;
  long long l = 1, r = 100, mid;
  while (l < r) {
    mid = (l + r) / 2;
    if (solve(mid, n, 10))
      r = mid;
    else
      l = mid + 1;
  }
  string x = "codeforces";
  long long z = l, p = pw(l, 10);
  long long y = z;
  if (p > n) y--;
  for (long long i = 0; i < 10; i++) {
    v.push_back(y);
  }
  for (long long i = 0; i <= 10; i++) {
    long long r = i;
    long long s = 1;
    for (long long j = 0; j < r; j++) s *= (y + 1);
    for (long long j = 0; j < 10 - r; j++) s *= y;
    if (s >= n) {
      z = r;
      break;
    }
  }
  for (long long i = 0; i < 10; i++) {
    long long a = y;
    if (i < z) a++;
    for (long long j = 0; j < a; j++) s += x[i];
  }
  cout << s << endl;
}
