#include <cstdio>

#include <cstring>

#include <algorithm>

#include <iostream>

using namespace std;

const int maxn =  + ;

int t1[maxn], t2[maxn], c[maxn];

bool cmp(int* r, int a, int b, int l) {

    return r[a] == r[b] && r[a + l] == r[b + l];

}

void da(int str[], int sa[], int Rank[], int lcp[], int n, int m) {

    ++n;

    int i, j, p, *x = t1, *y = t2;

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

    //        puts("hha");

    for (i = ; i < n; ++i) c[x[i] = str[i]]++;

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

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

    for (j = ; j <= n; j <<= ) {

        p = ;

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

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

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

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

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

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

        swap(x, y);

        p = ; x[sa[]] = ;

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

            x[sa[i]] = cmp(y, sa[i - ], sa[i], j) ? p -  : p++;

        }

        if (p >= n)break;

        m = p;

    }

    int k = ;

    n--;

    for (i = ; i <= n; ++i) Rank[sa[i]] = i;

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

        if (k)--k;

        j = sa[Rank[i] - ];

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

        lcp[Rank[i]] = k;

        //cout << k << endl;

    }

}

int lcp[maxn], a[maxn], sa[maxn], Rank[maxn];

char s[maxn];

int d[maxn][];

int len;

void rmq_init(int* A, int n) {

    for (int i = ; i < n; ++i) d[i][] = A[i];

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

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

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

}

int ASK(int l, int r) {

    int k = ;

    while (( << (k + )) <= r - l + )++k;

    return min(d[l][k], d[r - ( << k) + ][k]);

}

int ask(int l, int r) {

    if (l == r) return len - sa[r]; /// l == r的话 是一个串， 返回本身的长度即可。

    return ASK(l + , r); ///否则在rmq查询。

}

//

int main() {

    //freopen("in.txt", "r", stdin);

    //freopen("outstd.txt", "w", stdout);

    int T;

    scanf("%d", &T);

    while (T--) {

        int k;

        scanf("%d", &k);

        scanf("%s", s);

        //puts(s);

        len = strlen(s);

        for (int i = ; i < len; ++i) {

            a[i] = s[i] - 'a' + ;

        }

        a[len] = ;

        da(a, sa, Rank, lcp, len, );

        rmq_init(lcp, len + );

        long long ans = ;

        if (k == )

        {

            for (int i = ; i <= len; i++)

            {

                int siz = len - sa[i];

                int des = ;

                if (i > ) des = max(des, ask(i - , i));

                if (i < len) des = max(des, ask(i, i + ));

                ans += siz - des;

            }

        }

        else

        {

            for (int i = ; i+k- <= len; i++)

            {

                int siz = ask(i, i + k - );

                int des = ;

                if (i > ) des = max(des, ask(i - , i + k - ));

                if (i + k <= len) des = max(des, ask(i, i + k));

                ans += siz - des;

            }

        }

        printf("%I64d\n", ans);

        /*

        long long ans = 0;

        for (int i = 1; i + k - 1 <= len; ++i) {

            ans += ask(i, i + k - 1);

            if (i - 1 > 0)ans -= ask(i - 1, i + k - 1); ///注意边界问题。

            if (i + k <= len)ans -= ask(i, i + k);

            if (i - 1 > 0 && i + k <= len)ans += ask(i - 1, i + k);

        }

        printf("%I64d\n", ans);*/

    }

    return ;

}