#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define Fr(i, l, r) for (int i = l; i <= r; ++i)
#define Rf(i, r, l) for (int i = r; i >= l; --i)

template<typename T> void Min(T& x, T y) {
    if (y < x) x = y;
}

template<typename T> void Max(T& x, T y) {
    if (y > x) x = y;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int T; cin >> T;
    while (T --> 0) {
        int n; cin >> n;
        map<int, int> cnt;
        for (int i = 1, j; i <= n; ++i) {
            cin >> j, ++cnt[j];
        }
        int m = 0;
        vector<int> b(1);
        for (auto [i, j] : cnt) {
            b.emplace_back(j), ++m;
        }
        int ans = b[m];
        for (int i = 1; i < m; ++i) {
            int tmp = b[i] | b[m];
            if (b[i] & b[m]) {
                tmp |= (1 << __lg(b[i] & b[m])) - 1;
            }
            ans = max(ans, tmp);
        }

        cout << ans << "\n";
    }

    return 0;
}