#include<iostream>
#include<algorithm>
#include<vector>
#define max 100000
typedef unsigned long long int ull;
using namespace std;
int main()
{
    int t,i,j;
    unsigned long int n;
    ull ar[max];
    pair<vector<ull>::iterator,vector<ull>::iterator> bounds;
    cin>>t;
    while(t--)
    {
              cin>>n;
              for( i=0;i<n;i++)
              {
                      cin>>ar[i];
              }

             vector<ull> v(ar,ar+n);
              sort (v.begin(), v.end());
              for(j=0;j<n;j++)
              {
              bounds=equal_range (v.begin(), v.end(), ar[j]);
              if(((bounds.second-v.begin())-1)==(bounds.first-v.begin()))
              {
              cout<<ar[j]<<"\n";
              break;
              }
              }
     }
     return 0;
}