#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

int main(){
    ll n;
    cin >> n;

    vector<ll> a(n);
    rep(i, n) cin >> a[i];

    vector<bool> check((1<<16), false);
    check[0] = true;
    rep(i, n){
        vector<bool> check2((1<<16), false);
        rep(j, 16){
            a[i] = a[i]/2 + (1<<15)*(a[i]%2);
            for(ll k=0; k<(1<<16); k++){
                if(check[k]){
                    check2[k | a[i]] = true;
                }
            }
        }
        for(ll k=0; k<(1<<16); k++) if(check2[k]) check[k] = true;
        if(check[(1<<16)-1]){
            break;
        }
    }

    for(ll i=(1<<16)-1; i>=0; i--){
        if(check[i]){
            cout << i << endl;
            return 0;
        }
    }
}