Codeforces Subsequences
Description
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least $k$ subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string $s$ is a subset of ten characters of $s$ that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least $k$ codeforces subsequences.
The only line contains a single integer $k$ ($1 \leq k \leq 10^{16})$.
Print a shortest string of lowercase English letters that contains at least $k$ codeforces subsequences. If there are several such strings, print any of them.
Input
The only line contains a single integer $k$ ($1 \leq k \leq 10^{16})$.
Output
Print a shortest string of lowercase English letters that contains at least $k$ codeforces subsequences. If there are several such strings, print any of them.
Samples
1
codeforces
3
codeforcesss