#include <bits/stdc++.h>
using namespace std;
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cerr << name << " : " << arg1 << '\n';
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cout.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}
long long pows(long long a, long long b) {
  long long res = 1;
  while (b > 0) {
    if (b & 1) res = res * a;
    a = a * a;
    b >>= 1;
  }
  return res;
}
long long powm(long long x, long long y, long long m = 1000000007) {
  x = x % m;
  long long res = 1;
  while (y) {
    if (y & 1) res = res * x;
    res %= m;
    y = y >> 1;
    x = x * x;
    x %= m;
  }
  return res;
}
long long modInverse(long long a, long long m = 1000000007) {
  if (m == 1) return 0;
  long long m0 = m, y = 0, x = 1;
  while (a > 1) {
    long long q = a / m, t = m;
    m = a % m, a = t;
    t = y;
    y = x - q * y;
    x = t;
  }
  if (x < 0) x += m0;
  return x;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n, m, i, j, k, x, y, v, z, t, e, f, p, q, g, l, r, w, h,
      count1 = 0, prod = 1, a, b, c, d, index, diff, ans = 0, sum = 0, sum1 = 0,
      sum2 = 0, flag = 0, flag1 = 0, flag2 = 0;
  string s, s1, s2;
  cin >> k;
  vector<long long> ar(10, 1);
  s = "codeforces";
  if (k == 1) {
    cout << s << "\n";
    return 0;
  }
  while (1) {
    long long pos = 0;
    while (prod < k && pos < 10) {
      prod /= ar[pos];
      ar[pos]++;
      prod *= ar[pos];
      pos++;
    }
    if (prod >= k) {
      break;
    }
  }
  for (i = 0; i < 10; i++) {
    for (j = 0; j < ar[i]; j++) {
      s1 += s[i];
    }
  }
  cout << s1;
}
