Codeforces Subsequences

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.

Input

The only line contains a single integer k (1 ≤ k ≤ 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.

Examples

Input

1

Output

codeforces

Input

3

Output

codeforcesss

inputFormat

Input

The only line contains a single integer k (1 ≤ k ≤ 10^{16}).

outputFormat

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.

Examples

Input

1

Output

codeforces

Input

3

Output

codeforcesss

样例

1

codeforces