#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;
	
}