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CF1682A.Palindromic Indices
Palindromic Indices
You are given a palindromic string of length .
You have to count the number of indices such that the string after removing from still remains a palindrome.
For example, consider = "aba"
- If we remove from , the string becomes "
ba" which is not a palindrome. - If we remove from , the string becomes "
aa" which is a palindrome. - If we remove from , the string becomes "
ab" which is not a palindrome.
A palindrome is a string that reads the same backward as forward. For example, "abba", "a", "fef" are palindromes whereas "codeforces", "acd", "xy" are not.
Input
The input consists of multiple test cases. The first line of the input contains a single integer — the number of test cases. Description of the test cases follows.
The first line of each testcase contains a single integer — the length of string .
The second line of each test case contains a string consisting of lowercase English letters. It is guaranteed that is a palindrome.
It is guaranteed that sum of over all test cases does not exceed .
Output
For each test case, output a single integer — the number of indices such that the string after removing from still remains a palindrome.
Note
The first test case is described in the statement.
In the second test case, the indices that result in palindrome after removing are . Hence the answer is .
In the third test case, removal of any of the indices results in "d" which is a palindrome. Hence the answer is .
Samples
3
3
aba
8
acaaaaca
2
dd
1
4
2
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