#pragma comment(linker, "/STACK:1024000000,1024000000")

#include <cstdio>

#include <string>

#include <cstdlib>

#include <cmath>

#include <iostream>

#include <cstring>

#include <set>

#include <queue>

#include <algorithm>

#include <vector>

#include <map>

#include <cctype>

#include <cmath>

#include <stack>

#include <sstream>

#include <list>

#include <assert.h>

#include <bitset>

#define debug() puts("++++");

#define gcd(a, b) __gcd(a, b)

#define lson l,m,rt<<1

#define rson m+1,r,rt<<1|1

#define fi first

#define se second

#define pb push_back

#define sqr(x) ((x)*(x))

#define ms(a,b) memset(a, b, sizeof a)

#define sz size()

#define pu push_up

#define pd push_down

#define cl clear()

#define all 1,n,1

#define FOR(x,n)  for(int i = (x); i < (n); ++i)

#define freopenr freopen("in.txt", "r", stdin)

#define freopenw freopen("out.txt", "w", stdout)

using namespace std;

typedef long long LL;

typedef unsigned long long ULL;

typedef pair<int, int> P;

const int INF = 0x3f3f3f3f;

const double inf = 1e20;

const double PI = acos(-1.0);

const double eps = 1e-8;

const int maxn = 1e5 + 50;

const int mod = 1000;

const int dr[] = {-1, 0, 1, 0};

const int dc[] = {0, 1, 0, -1};

const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};

int n, m;

const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

inline bool is_in(int r, int c) {

  return r > 0 && r <= n && c > 0 && c <= m;

}

struct Array{

  int s[maxn], sa[maxn], t[maxn], t2[maxn];

  int h[maxn], r[maxn], c[maxn];

  int n;

  int dp[maxn][20];

  void init(){ n = 0;  memset(sa, 0, sizeof sa); }

  void build_sa(int m){

    int *x = t, *y = t2;

    for(int i = 0; i < m; ++i)  c[i] = 0;

    for(int i = 0; i < n; ++i)  ++c[x[i] = s[i]];

    for(int i = 1; i < m; ++i)  c[i] += c[i-1];

    for(int i = n-1; i >= 0; --i)  sa[--c[x[i]]] = i;

    for(int k = 1; k <= n; k <<= 1){

      int p = 0;

      for(int i = n-k; i < n; ++i)  y[p++] = i;

      for(int i = 0; i < n; ++i)  if(sa[i] >= k)  y[p++] = sa[i] - k;

      for(int i = 0; i < m; ++i)  c[i] = 0;

      for(int i = 0; i < n; ++i)  ++c[x[y[i]]];

      for(int i = 1; i < m; ++i)  c[i] += c[i-1];

      for(int i = n-1; i >= 0; --i)  sa[--c[x[y[i]]]] = y[i];

      swap(x, y);

      p = 1;  x[sa[0]] = 0;

      for(int i = 1; i < n; ++i)

        x[sa[i]] = y[sa[i-1]] == y[sa[i]] && y[sa[i-1]+k] == y[sa[i]+k] ? p-1 : p++;

      if(p >= n)  break;

      m = p;

    }

  }

  void getHight(){

    int k = 0;

    for(int i = 0; i < n; ++i)  r[sa[i]] = i;

    for(int i = 0; i < n; ++i){

      if(k)  --k;

      int j = sa[r[i]-1];

      while(s[i+k] == s[j+k])  ++k;

      h[r[i]] = k;

    }

  }

  void rmq_init(){

    for(int i = 1; i <= n; ++i)  dp[i][0] = h[i];

    for(int j = 1; (1<<j) <= n; ++j)

      for(int i = 1; i + (1<<j) <= n; ++i)

        dp[i][j] = min(dp[i][j-1], dp[i+(1<<j-1)][j-1]);

  }

  int query(int L, int R){

    if(L == R)  return L;

    ++L;

    int k = int(log(R-L+1) / log(2.0));

    return min(dp[L][k], dp[R-(1<<k)+1][k]);

  }

};

char s[maxn];

Array arr;

int main(){

  int T;  cin >> T;

  while(T--){

    int k;

    arr.init();

    scanf("%d", &k);

    scanf("%s", s);

    for(int i = 0; s[i]; ++i)

      arr.s[arr.n++] = s[i] - 'a' + 1;

    arr.s[arr.n++] = 0;

    arr.build_sa(28);

    arr.getHight();

    arr.rmq_init();

    int ans = 0;

    for(int i = 1; i < arr.n; ++i){

      int l = i+k-1 < arr.n ? arr.query(i, i+k-1) : 0;

      int x = i-1 > 0 && i+k-1 < arr.n ? arr.query(i-1, i+k-1) :0;

      int y = i+k < arr.n ? arr.query(i, i+k) : 0;

      int z = i-1 > 0 && i+k < arr.n ? arr.query(i-1, i+k) : 0;

      ans += l - x - y + z;

    }

    printf("%d\n", ans);

  }

  return 0;

}