B"Serval loves Brain Power and his brain power problem. Serval defines that a string T is powerful iff T can be obtained by concatenating some string T' multiple times. Formally speaking, T is powerful iff there exist a string T' and an integer k geq 2 such that T= underbrace{T'+T'+ ... +T'}_{k text{ times}} For example, gogogo is powerful because it can be obtained by concatenating go three times, but power is not powerful. Serval has a string S consists of lowercase English letters. He is curious about the longest powerful subsequence of S , and he only needs you to find out the length of it. If all the non-empty subsequences of S is not powerful, the answer is considered to be 0 . A string a is a subsequence of a string b if a can be obtained from b by the deletion of several (possibly, zero or all) characters. The first line contains a single string S ( |S| <= q 80 ) consisting of lowercase English letters. Print a single integer -- the length of the longest powerful subsequence of S . If all the non-empty subsequences of S is not powerful, print 0 . For the first sample, all of the non-empty subsequences of buaa are listed below: Since texttt{aa} = texttt{a} + texttt{a} , aa is a powerful subsequence. It can be shown that aa is the only powerful subsequence among them. So the answer is 2 . For the second sample, the longest powerful subsequence is codcod from codeforcesround. So the answer is 6 . "...