#include <bits/stdc++.h>
 
using namespace std;
 
void solve() {
 
	int n;
 
	cin >> n;
 
	vector<long long> nums(n + 1);
	vector<long long> count(30, 0);
 
	for(int i = 1; i <= n; i++) {
 
		cin >> nums[i];
 
		for(int j = 0; j < 30; j++) {
 
			count[j] = count[j] + ((nums[i] >> j) & 1);
 
		}
 
	}
 
	long long ans = 0;
 
	for(int i = 1; i <= n; i++) {
 
		long long sum = 0;
 
		for(int j = 0; j < 30; j++) {
 
			bool flags = ((nums[i] >> j) & 1);
 
			if(flags) {
 
				sum = sum + (1 << j) * (n - count[j]);
 
			}
 
			else {
 
				sum = sum + (1 << j) * count[j];
 
			}
 
		}
 
		ans = max(ans, sum);
 
	}
 
	cout << ans << endl;
 
}
 
int main() {
 
	ios_base::sync_with_stdio(false);
	cin.tie(0);
 
	int t;
 
	cin >> t;
 
	while(t--) {
 
		solve();
 
	}
 
	return 0;
 
}
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