#include <bits/stdc++.h>
#pragma GCC optimize("-O3")
using namespace std;
struct debugger {
  template <typename T>
  debugger& operator,(const T& v) {
    cerr << v << " ";
    return *this;
  }
} dbg;
bool sortbysec(const pair<long long, long long>& a,
               const pair<long long, long long>& b) {
  if (a.second == b.second) return a.first < b.first;
  return (a.second < b.second);
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long isPrime(long long n) {
  if (n < 2) return 0;
  if (n < 4) return 1;
  if (n % 2 == 0 or n % 3 == 0) return 0;
  for (long long i = 5; i * i <= n; i += 6)
    if (n % i == 0 or n % (i + 2) == 0) return 0;
  return 1;
}
long long modexpo(long long x, long long p) {
  long long res = 1;
  x = x % 1000000007;
  while (p) {
    if (p % 2) res = res * x;
    p >>= 1;
    x = x * x % 1000000007;
    res %= 1000000007;
  }
  return res;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long t = 1;
  while (t--) {
    long long k;
    cin >> k;
    long long a[10] = {};
    for (long long i = 0; i < 10; ++i) {
      a[i] = 1;
    }
    long long p = 0;
    long long prod = 1;
    while (prod < k) {
      prod /= a[p];
      a[p]++;
      prod *= a[p];
      p++;
      p %= 10;
    }
    for (long long i = 0; i < a[0]; ++i) {
      cout << 'c';
    }
    for (long long i = 0; i < a[1]; ++i) {
      cout << 'o';
    }
    for (long long i = 0; i < a[2]; ++i) {
      cout << 'd';
    }
    for (long long i = 0; i < a[3]; ++i) {
      cout << 'e';
    }
    for (long long i = 0; i < a[4]; ++i) {
      cout << 'f';
    }
    for (long long i = 0; i < a[5]; ++i) {
      cout << 'o';
    }
    for (long long i = 0; i < a[6]; ++i) {
      cout << 'r';
    }
    for (long long i = 0; i < a[7]; ++i) {
      cout << 'c';
    }
    for (long long i = 0; i < a[8]; ++i) {
      cout << 'e';
    }
    for (long long i = 0; i < a[9]; ++i) {
      cout << 's';
    }
    cout << "\n";
  }
}
