#include <bits/stdc++.h>
using namespace std;
char s[] = "codeforces";
long long k, i, m = 1, a[16];
int main() {
  for (i = 10; i--; a[i] = 1)
    ;
  for (scanf("%I64d", &k), i = 0; m < k;
       m /= a[i], m *= ++a[i], 10 == ++i ? i = 0 : 0)
    ;
  for (i = 0; i < 10; ++i)
    for (; a[i]--; printf("%c", s[i]))
      ;
  exit(0);
}
