#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using Graph=vector<vector<int>>;
#define INF 1000000000

int main(){
  int N;
  cin>>N;
  ll sum=0;
  for(int i=0;i<N;i++){
    ll A;
    cin>>A;
    sum|=A;
  }

  int i=0;
  while(((sum>>i)&1)==1){
    i++;
  }
  cout<<(1LL<<i)<<'\n';
}