#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
const int mod = 1000000007;
const long long INF = 1LL << 60;

int main()
{
  int N;
  cin >> N;

  vector<long long> a(N);
  rep(i,N){
    cin >> a[i];
  }

  vector<int> keta(64,0);
  rep(i,N){
    rep(j,62){
      keta[j]+=a[i]%2;
      a[i]/=2;
    }
  }
  long long ans=1;
  rep(i,64){
    if(keta[i]==0){
      cout << ans << endl;
      return 0;
    }
    ans*=2LL;
  }
  
  
}