#include <bits/stdc++.h>
using namespace std;
#define ls u << 1
#define rs u << 1 | 1
#define LL long long
#define int long long
#define PII pair <int, int>
#define fi first
#define se second
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define i128 __int128
#define pcnt(x) __builtin_popcount(x)
#define mem(a,goal) memset(a, (goal), sizeof(a))
#define rep(x,start,end) for(int x = (start) - ((start) > (end)); x != (end) - ((start) > (end)); ((start) < (end) ? x ++ : x --))
#define aLL(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
const int INF = 998244353;
const int mod = 1e9 + 7;
const int N = 100010;
int a[N];

void solve()
{
    int n;
    cin >> n;
    int res = -1;
    vector<int> a(n, 0), cnt(31, 0);
    for(int i = 0; i < n; ++ i)
    {
        cin >> a[i];
        for(int j = 0; j < 31; ++ j)
        {
            if(a[i] >> j & 1) cnt[j] ++;
        }
    }
    for(int i = 0; i < n; ++ i)
    {
        int t = 0;
        for(int j = 0; j < 31; ++ j)
        {
            int tmp = a[i] >> j & 1;
            if(tmp) t += (1 << j) * (n - cnt[j]);
            else t += (1 << j) * cnt[j];
        }
        res = max(res, t);
    }
    cout << res << '\n';
}

signed main()
{
    int t = 1;
    cin >> t;
    while (t --) solve();
    return 0;
}