#include <bits/stdc++.h>
#include <atcoder/string>
using namespace std;
int main(){
  int T;
  cin >> T;
  for (int i = 0; i < T; i++){
    int N;
    cin >> N;
    string S;
    cin >> S;
    vector<int> Z = atcoder::z_algorithm(S);
    int ans = 0;
    for (int j = 1; j < N; j++){
      int x = Z[j];
      x = min({x, j, N - j});
      if (x < j && x < N - j){
        if (S[x] < S[j + x]){
          ans++;
        }
      } else if (x < N - j){
        ans++;
      }
    }
    cout << ans << endl;
  }
}