#include <bits/stdc++.h>
using namespace std;
const int MAX_N = int(1e6) + 10;
const long long int MOD = 1e9 + 7;
const long long int INF = 1e18;
inline long long int mul(long long int a, long long int b) {
  a = (a + MOD) % MOD;
  b = (b + MOD) % MOD;
  long long int c = a * b;
  c = (c + MOD) % MOD;
  return c;
}
inline long long int add(long long int a, long long int b) {
  a = (a + MOD) % MOD;
  b = (b + MOD) % MOD;
  long long int ans = (a + b);
  ans = (ans + MOD) % MOD;
  return ans;
}
long long int power(long long int a, long long int b, long long int c = 0) {
  long long int ans = 1;
  while (b) {
    if (b & 1) {
      ans = mul(ans, a);
    }
    a = mul(a, a);
    b = b / 2;
  }
  return ans;
}
long long int fact[1000005];
long long int inv[1000005];
inline long long int fun(long long int x, long long int y) {
  return mul(mul(fact[x], inv[x - y]), inv[y]);
}
string s = "codeforces";
long long int k;
map<int, int> mp;
int main() {
  cin >> k;
  for (int i = 0; i < 10; i++) {
    mp[i] = 1;
  }
  long long int p = 1;
  while (p < k) {
    int indx = 0;
    int ans = INT_MAX;
    for (int i = 0; i < 10; i++) {
      if (ans > mp[i]) {
        ans = mp[i];
        indx = i;
      }
    }
    mp[indx]++;
    p = 1LL;
    for (int i = 0; i < 10; i++) {
      p = p * 1LL * mp[i];
    }
  }
  for (int i = 0; i < 10; i++) {
    for (int j = 0; j < mp[i]; j++) {
      cout << s[i];
    }
  }
}
