#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return true; } return false; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return true; } return false; }
#define vi vector<int>
#define vl vector<ll>
#define vii vector<pair<int,int>>
#define vll vector<pair<ll,ll>>
#define vvi vector<vector<int>>
#define vvl vector<vector<ll>>
#define vvii vector<vector<pair<int,int>>>
#define vvll vector<vector<pair<ll,ll>>>
#define vst vector<string>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define mkunique(x) sort(all(x));(x).erase(unique(all(x)),(x).end())
#define fi first
#define se second
#define mp make_pair
#define si(x) int(x.size())
const int mod=998244353,MAX=300005;
const ll INF=15LL<<58;

int f(ll x){
    if(x==0) return 1;
    ll a=__builtin_clzll(x);
    a=64-a;
    return a-__builtin_popcountll(x);
}

bool check(vi S,ll st){
    for(int i=0;i<si(S);i++){
        if(f(st+i)!=S[i]) return false;
    }
    return true;
}

int main(){
    
    std::ifstream in("text.txt");
    std::cin.rdbuf(in.rdbuf());
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    int Q;cin>>Q;
    while(Q--){
        ll N;cin>>N;
        ll n=1;
        while(n<N) n*=2;
        n*=2;
        vi A(N);
        for(int i=0;i<N;i++){
            cin>>A[i];
        }
        ll ans=INF;
        for(ll x=0;x<=n;x++){
            if(check(A,x)){
                ans=x;
                break;
            }
        }
        if(ans!=INF){
            cout<<ans<<"\n";
            continue;
        }
    }
}