There is a string that consists of lowercase english alphabets and we have to make the string a palindrome
For this, we have \(2\) types of operations
1. Re-arrange the string however you want (this operation is free)
2. Add a new character to the end of the string (this operation will cost 1Re)

Your task is to calculate the minimum amount of money to make the string a palindrome

Input Format:
The first line contains one integer \(T\) the number of test cases
The first line of every test case consists of \(N\), the length of the string 
The second line of every test case contains string \(S\)

Output Format:
For every test case output one integer, the minimum amount of money required to make the string a palindrome

Constraints:

\(1 \leq T \leq 100 \\ 1 \leq N \leq 10^5\)