题目描述
We will call a string that can be obtained by concatenating two equal strings an even string. For example, xyzxyz and aaaaaa are even, while ababab and xyzxy are not.
You are given an even string S consisting of lowercase English letters. Find the length of the longest even string that can be obtained by deleting one or more characters from the end of S. It is guaranteed that such a non-empty string exists for a given input.
Constraints
- $2 \leq |S| \leq 200$
- S is an even string consisting of lowercase English letters.
- There exists a non-empty even string that can be obtained by deleting one or more characters from the end of S.
Input
Input is given from Standard Input in the following format:
S
Output
Print the length of the longest even string that can be obtained.
Examples
Input
abaababaab
Output
6
Input
xxxx
Output
2
Input
abcabcabcabc
Output
6
Input
akasakaakasakasakaakas
Output
14
输入格式
见题面
输出格式
见题面
样例输入
abaababaab
样例输出
6