GOCTC04: Google's Online Challenge - IN 2021 Cloud TSC
Anyone of you participated in google online challenge?
A Special String: You are given a string S consisting of lowercase Latin alphabets a-z. Find the minimum number of characters that must be changed to make S special. A string S is said to be special if and only if for all (S[i] , S[j] ) where (1 ≤ i ≤ N/2) and (N/2 + 1 ≤ j ≤ N) one of the following condition is true

S[i] > S[j]
S[i] < S[j]
S[i] = S[j]
S[i] represents the ith character of string S (1 based Indexing ).

Input Format:

The first line contains an integer T denoting the number of test cases.
The first line of each test case contains an integer N denoting the length of S.
The second line of each test case contains a string S.
Output format: Print an integer denoting the minimum number of changes required for each test case in a new line.

Constraints

1 ≤ T ≤ 5

1 ≤ N ≤ 103

N is even

Example :

Input: 1
6
aababc
Output: 2
Explanation: Change S[4] = ‘d’ (1 based indexing) Change S[5] = ‘d’ New string = ‘aabddc’ Now all pair (S[i],S[j]) satisfy the second condition, S[i] < S[j]

Generating Sequence: You are given two strings A of length N and B of length M. These strings contain lowercase English alphabets. You are also given an integer K. You can change the character of x string A to any other characters y. The cost of this conversion is abs( ASCII(x)- ASCII(y) ). Find the minimum cost required such that the length of the longest common subsequence (LCS) of A and B is at least K.

Note:

A subsequence of A string can be obtained by deleting zero or more characters in A.
The longest common subsequence of two strings of A and B is a subsequence of A and B and has the maximum length among all strings that are a subsequence of A and B that would be multiple subsequences for two provided strings for example an LCS of vera and eats is ea.
Input Format:

The first line contains an integer T denoting the number of test cases for each test case.
The first line of each test case contains three space-separated integers N, M, and K.
The next line of each test case contains a string A.
The next line of each test case contains a string B.
Output format: For each test case, print the minimum cost required in a new line.

Constraints

1 ≤ T ≤ 10

1 ≤ N, M ≤ 200

0 ≤ K ≤ min( N, M )

Example:

Input: 2
5 4 3
abcba
acyx
3 3 3
abc
abc
Output: 22
0