Raja loves Strings. In Strings he specially loves palindromes.Palindromes

are strings that read the same when read forward or backwards. Here

Palindromes considered are only of even length(maybe 0). His Teacher

gave me him a long string consisting of only digits as a gift on his

birthday. Now Raja wants to know The longest subarray whose elements

(i.e digits) can be rearranged to form a palindrome of even length. Raja is

unable to figure out the solution to the problem so he asks for your help.

INPUT SPECIFICATION -

The function contains one argument - A String S consisting of digits (0-9).

First and only line of input consists of S (1 <= |S| <= 100000).

OUTPUT SPECIFICATION -

You must return a single integer denoting the longest subarray whose

elements (digits) can be rearranged to form a palindrome of even

length.If no such subarray can be found return 0.

Example -

Sample Test Case 1

Input

12345354987

Output

6

Explanation : No subarray can be rearranged to form even length of palindrome .Hence 0.

Explanation : Here the longest subarray is 345354 which can be rearranged to form 345543 which is a palindrome of even length 6.Hence and is 6.

Sample Test Case 2-

Input

12345

Output

0