#include<iostream>
using namespace std;
int b[1000];
int main()
{
ios::sync_with_stdio(false);
int n;
cin>>n;
while(n--)
{
int m;
cin>>m;
int result;
int ans = 0;
for(int i = 0;i < m;i++)
{
int num = 0;
cin>>b[i];
for(int j = 0;j <= b[i];j++)
num += (j | b[i]);
if(ans < num)
{
ans = num;
result = b[i];
}
}
cout<<result<<endl;
}
return 0;
}