Count Removable Indices

Given a lowercase string that is already a palindrome, count the indices whose removal still leaves a palindrome; equal characters at different indices are counted separately.

输入格式

A single line containing a palindrome string of length 2..100000.

输出格式

Output a single integer answer.

样例 1

输入：

zzz

输出：

3

样例 2

输入：

abba

输出：

2

样例 3

输入：

abcba

输出：

1

样例说明

Example 1: removing any z gives zz, 3 indices in total. Example 2: only one of the two middle b can be removed, giving aba, 2 in total. Example 3: only removing the center c gives abba, so the answer is 1.