import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int t = sc.nextInt();
        StringBuilder sb = new StringBuilder();
        while (t-- > 0) {
            int n = sc.nextInt();
            char[] inputs = sc.next().toCharArray();
            long[][] hashes = new long[10][n];
            for (int i = 0; i < n; i++) {
                hashes[0][i] = inputs[i] - 'a';
            }
            for (int i = 1; i < 10; i++) {
                for (int j = 0; j + i < n; j++) {
                    hashes[i][j] = hashes[i - 1][j] * 26 + hashes[0][j + i];
                }
            }
            int ans = 0;
            for (int i = 1; i < n; i++) {
                int left = i;
                int right = n - i;
                int idx = 0;
                boolean decided = false;
                while (left - idx > 0 && right - idx> 0) {
                    int length = Math.min(10, Math.min(left - idx, right - idx));
                    if (hashes[length - idx - 1][0 + idx] == hashes[length - idx - 1][i + idx]) {
                        idx += 10;
                    } else if (hashes[length - idx - 1][0 + idx] < hashes[length - idx - 1][i + idx]) {
                        ans++;
                        decided = true;
                        break;
                    } else {
                        decided = true;
                        break;
                    }
                }
                if (!decided) {
                    if (left < right) {
                        ans++;
                    }
                }
            }
            sb.append(ans).append("\n");
        }
        System.out.print(sb);
    }
    
} 
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}