#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using ull=unsigned long long;
const ll MOD=1000000000+7;
#define rep(I,N) for(int I=0;I<N;I++)
#define ALL(x) x.begin(),x.end()
#define PRINTV(x) for(auto i:x){for(auto j:i){printf("%d\t",j);}printf("\n");}
using vec = vector<int>;
using vvec = vector<vector<int>>;

ll lcm(ll a,ll b){
    return a/__gcd(a,b)*b;
}

int main(){
    ll n;
    cin >> n;
    vector<ll> a(n);
    rep(i,n)cin >> a[i];
    ll ored=0;
    ll ans=1;
    rep(i,n)ored|=a[i];
    while(1){
        if(!(ored&1))break;
        ored=ored >> 1;
        ans*=2;
    }
    printf("%lld\n",ans);
}