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

typedef long long ll;
const int N = 100005;

int a[N];
int lg[N];


int ct[N];

int getans(int x, int y) {
	if (x & y == 0) {
		return x | y;
	} else {
		return x | y | ((1 << lg[x & y]) - 1);
	}
}

void solve() {
	
	for (int i = 0; i <= 100000; i++) {
		ct[i] = 0;
	}
	
	int n;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		int x;
		cin >> x;
		ct[x]++;
	}
	sort(ct + 1, ct + 1 + n);
	
	int cntx = 0, cnty = 0;
	for (int i = 1; i <= n; i++) {
		if (ct[i] >= cntx) {
			cnty = cntx;
			cntx = ct[i];
		} else {
			cnty = ct[i];
		}
	}
	
//	cout << (cntx | cnty | ((1 << (lg[cntx & cnty])) - 1)) << '\n';

//	int k = cntx & cnty;
	cout << getans(cntx, cnty) << '\n';
//	while(k > (k & (-k))) k -= k & (-k);
//	k--;
//	if (k < 0) k = 0;
	
	
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	lg[0] = -1;
	for (int i = 1; i <= 100000; i++) {
		lg[i] = lg[i / 2] + 1;
	}
	
	int T;
	cin >> T;
	while(T--) {
		solve();
	}


	return 0;
}