You're given a string S, consisting only of lowercase Latin letters. Find whether it is possible to convert it into a palindrome by inserting only one character.

If it is possible, return the index (0-based Index) where the character should be inserted. If there is more than one, return the smallest one. If it is not possible, return -1.

A single line containing the word to transform S.

The index (0-based Index) where the character should be inserted or -1.

1 ≤ length of S ≤ 100

Input

aa

Output

0