#include <bits/stdc++.h>
#define rep(i, a, b) for (int i = a, I = b; i <= I; ++i)
#define per(i, a, b) for (int i = a, I = b; i >= I; --i)
using namespace std;
using i64 = long long;
using i128 = __int128_t;
template<typename T> void up(T &x, T y) { x < y ? x = y : 0; }
template<typename T> void down(T &x, T y) { x > y ? x = y : 0; }

const int N = 1000005;
using pii = pair<int, int>;
int n, rk[N], sa[N], pot[N], h[N], par[N], siz[N];
char s[N];
pair<pii, int> x[N], y[N];
vector<int> e[N];
i64 cnt[N];

int find(int x) {
    while (x != par[x]) x = par[x] = par[par[x]];
    return x;
}
void merge(int u, int v, int t) {
    int x = find(u), y = find(v);
    cnt[siz[x]] -= t, cnt[siz[y]] -= t;
    par[x] = y, siz[y] += siz[x];
    cnt[siz[y]] += t;
}

void solve() {
    cin >> n;
    rep(i, 1, n) cin >> s[i];
    for (int i = 1; i <= n; ++i) rk[i] = s[i];
    for (int k = 1, t = 0; k <= n; k <<= 1) {
        for (int i = 1; i <= n; ++i) x[i] = {pii(rk[i], (i + k) <= n ? rk[i + k] : 0), i};
        if (k == 1) {
            sort(x + 1, x + n + 1);
        } else {
            memset(pot + 1, 0, t * 4);
            for (int i = 1; i <= n; ++i) ++pot[x[i].first.second];
            for (int i = 1; i <= t; ++i) pot[i] += pot[i - 1];            
            for (int i = 1; i <= n; ++i) y[pot[x[i].first.second]--] = x[i];
            memset(pot + 1, 0, t * 4);
            for (int i = 1; i <= n; ++i) ++pot[y[i].first.first];
            for (int i = 1; i <= t; ++i) pot[i] += pot[i - 1];
            for (int i = n; i; --i) x[pot[y[i].first.first]--] = y[i];
        }
        int t1 = 0;
        for (int i = 1; i <= n; ++i) {
            if (i == 1 || x[i].first.first != x[i - 1].first.first || x[i].first.second != x[i - 1].first.second) ++t1;
            rk[x[i].second] = t1;
        }
        t = t1;
        if (t == n) break;
    }
    for (int i = 1; i <= n; ++i) sa[rk[i]] = i;
    rep(i, 1, n) e[i].clear();
    rep(i, 1, n) par[i] = i, siz[i] = 1, cnt[i] = 0;
    for (int i = 1, k = 0; i <= n; ++i) {
        if (k) --k;
        if (rk[i] == 1) continue;
        int j = sa[rk[i] - 1];
        while (max(i, j) + k <= n && s[i + k] == s[j + k]) ++k;
        h[i] = k;
        e[h[i]].push_back(rk[i]);
    }

    per(i, n, 1) {
        for (auto pos : e[i]) merge(pos - 1, pos, i);
    }
    cnt[1] = 1ll * n * (n + 1) / 2;
    rep(i, 2, n) cnt[1] -= cnt[i] * i;
    // rep(i, 1, n) cerr << cnt[i] << " \n"[i == n];

    i64 ans = 0;
    priority_queue<i64, vector<i64>, greater<i64>> pq;
    int last = -1;
    rep(i, 1, n) {
        if (!cnt[i]) continue;
        if (~last) {
            ans += last + i;
            --cnt[i];
            if (last + i <= n) ++cnt[last + i];
            else pq.push(last + i);
            last = -1;
        }
        i64 cur = cnt[i] / 2;
        ans += cur * i * 2;
        cnt[i] -= cur * 2;
        if (i * 2 <= n) cnt[i * 2] += cur;
        else while (cur--) pq.push(i * 2);
        if (cnt[i]) last = i;
    }

    if (~last) pq.push(last);
    while ((int) pq.size() > 1) {
        i64 x = pq.top(); pq.pop();
        i64 y = pq.top(); pq.pop();
        ans += x + y;
        pq.push(x + y);
    }

    i64 ans1 = 1ll * n * (n + 1) / 2;
    i64 g = __gcd(ans, ans1);
    ans /= g, ans1 /= g;
    if (ans1 == 1) {
        cout << ans << "\n";
    } else {
        cout << ans << "/" << ans1 << "\n";
    }
}

int main() {
	ios::sync_with_stdio(0), cin.tie(0);

    int t; cin >> t;
    while (t--) solve();    

	return 0;
}