B. Codeforces Subsequencestime limit per test2 secondsmemory limit per test512 megabytesinputstandard inputoutputstandard outputKarl 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.InputThe only line contains a single integer k (1 \leq k \leq 10^{16}).OutputPrint a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.ExamplesInput
1
Output
codeforces
Input
3
Output
codeforcesss
1

codeforces 
['brute force', 'constructive algorithms', 'greedy', 'math', 'strings', '*1500']