CF1368B.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.

卡尔喜欢 Codeforces 和子序列。他想找到一个由小写英文字母组成的字符串，使得其中至少包含 $k$ 个子序列 codeforces。在所有满足条件的字符串中，卡尔希望找到最短的一个。

形式化地，字符串 $s$ 的一个 codeforces 子序列是指 $s$ 中按从左到右顺序选取的十个字符，它们恰好构成字符串 codeforces。例如，codeforces 本身恰好包含一个 codeforces 子序列；而 codeforcesisawesome 包含四个 codeforces 子序列：
codeforcesisawesome，
codeforcesisawesome，
codeforcesisawesome，
codeforcesisawesome。

请帮助卡尔找出任意一个最短的、至少包含 $k$ 个 codeforces 子序列的字符串。

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

唯一的一行包含一个整数 $k$（$1 \leq k \leq 10^{16}$）。

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.

输出一个最短的小写英文字母字符串，使其至少包含 $k$ 个子序列 "codeforces"。如果存在多个满足条件的字符串，输出其中任意一个即可。