#include<bits/stdc++.h>
#include<vector>
using namespace std;

typedef long long ll;
const int N = 100005;

int a[N];

struct Node {
	int op, x;
};

vector<Node> ans;
vector<int> pos[1010];

void dfs(int l, int r, int val) {
	if (val != a[l]) {
		for (int i = l; i < r; i++) {
			for (int j : pos[a[i]]) {
				ans.push_back({2, j});
			}
		}

		for (int i = val + 1; i < a[l]; i++) {
			ans.push_back({1, i});
		}
	}

	if (r == l + 1) {
		return;
	}

	int m = l + r >> 1;
	dfs(m, r, a[l]);
	dfs(l, m, a[l]);


}

int ct[N];

void solve() {

	int n;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		int x;
		cin >> x;
		ct[x]++;
	}

	if (n == 1) {
		cout << ct[1] << '\n';
		return;
	}

	sort(ct + 1, ct + 1 + n);
	cout << (ct[n] | ct[n - 1] | (1 << (__lg(ct[n] & ct[n - 1])) - 1)) << '\n';

}

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

	int T;
	cin >> T;
	while(T--) {
		solve();
	}


	return 0;
}