#include <iostream>
#include<vector>
#include<utility>
#include<map>
#include<cmath>
using namespace std;
#define ll long long
int main()
{
    ll t;
    cin >> t;
    while(t--){
      vector<ll> setBitCount(30,0);
      vector<ll> arr;
      ll n;
      cin >> n;
      for(ll i=0;i<n;++i){
        ll temp;
        cin >> temp;
        arr.emplace_back(temp);
        ll k=0;
        while(temp!=0){
          if(temp&1==1) setBitCount[k]++;
          temp=temp>>1;
          k++;
        }
      }
      ll x = 0;
      ll limit=0;
      for(ll i=29;i>=0;i--){
        if(setBitCount[i]>0){
          limit = i;
          break;
        }
      }
      for(ll i=0;i<=limit;++i){
        if(setBitCount[i]>n/2) x = x + pow(2,i);
      }
      ll minSum =0;
      for(ll i=0;i<n;++i){
        minSum = minSum + arr[i]^x;
      }
      cout << minSum << endl;
    }

    return 0;
}