#include <bits/stdc++.h>
#pragma GCC optimization("O3")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC target("sse4.2")
using namespace std;
template <typename T>
istream &operator>>(istream &in, vector<T> &v) {
  for (auto &i : v) cin >> i;
  return in;
}
template <typename T>
ostream &operator<<(ostream &out, vector<T> &v) {
  for (auto &i : v) cout << i << " ";
  return out;
}
void solve() {
  long long int i, j, n, a, b, c, d, m, k, sum = 0, ans = 0, cnt = 0, r = 0,
                                           e = 0, x = 0, y = 0;
  string str, s1, om, s;
  map<char, long long int> mp, mp1;
  set<long long int> st;
  cin >> n >> s;
  s1 = s;
  sort(s1.begin(), s1.end());
  for (i = 0; i < n; i++) {
    if (s[i] == s1[i]) cnt++;
  }
  ans = n - cnt;
  cout << ans << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  long long int tc;
  cin >> tc;
  while (tc--) {
    solve();
  }
  return 0;
}

### Prompt

Construct a cpp code solution to the problem outlined:

A string s of length n, consisting of lowercase letters of the English alphabet, is given.

You must choose some number k between 0 and n. Then, you select k characters of s and permute them however you want. In this process, the positions of the other n-k characters remain unchanged. You have to perform this operation exactly once.

For example, if s="andrea", you can choose the k=4 characters "a_d_ea" and permute them into "d_e_aa" so that after the operation the string becomes "dneraa".

Determine the minimum k so that it is possible to sort s alphabetically (that is, after the operation its characters appear in alphabetical order).

Input

The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases. Then t test cases follow.

The first line of each test case contains one integer n (1 ≤ n ≤ 40) — the length of the string.

The second line of each test case contains the string s. It is guaranteed that s contains only lowercase letters of the English alphabet.

Output

For each test case, output the minimum k that allows you to obtain a string sorted alphabetically, through the operation described above.

Example

Input


4
3
lol
10
codeforces
5
aaaaa
4
dcba


Output


2
6
0
4

Note

In the first test case, we can choose the k=2 characters "_ol" and rearrange them as "_lo" (so the resulting string is "llo"). It is not possible to sort the string choosing strictly less than 2 characters.

In the second test case, one possible way to sort s is to consider the k=6 characters "_o__force_" and rearrange them as "_c__efoor_" (so the resulting string is "ccdeefoors"). One can show that it is not possible to sort the string choosing strictly less than 6 characters.

In the third test case, string s is already sorted (so we can choose k=0 characters).

In the fourth test case, we can choose all k=4 characters "dcba" and reverse the whole string (so the resulting string is "abcd").

### Response

```cpp
#include <bits/stdc++.h>
#pragma GCC optimization("O3")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC target("sse4.2")
using namespace std;
template <typename T>
istream &operator>>(istream &in, vector<T> &v) {
  for (auto &i : v) cin >> i;
  return in;
}
template <typename T>
ostream &operator<<(ostream &out, vector<T> &v) {
  for (auto &i : v) cout << i << " ";
  return out;
}
void solve() {
  long long int i, j, n, a, b, c, d, m, k, sum = 0, ans = 0, cnt = 0, r = 0,
                                           e = 0, x = 0, y = 0;
  string str, s1, om, s;
  map<char, long long int> mp, mp1;
  set<long long int> st;
  cin >> n >> s;
  s1 = s;
  sort(s1.begin(), s1.end());
  for (i = 0; i < n; i++) {
    if (s[i] == s1[i]) cnt++;
  }
  ans = n - cnt;
  cout << ans << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  long long int tc;
  cin >> tc;
  while (tc--) {
    solve();
  }
  return 0;
}

```