#include <bits/stdc++.h>
#include <complex>
#include <random>
using namespace std;
//#include <atcoder/all>
//using namespace atcoder;
using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vvvvll = vector<vvvll>;
using vvvvvll = vector<vvvvll>;
using vvvvvvll = vector<vvvvvll>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vvvb = vector<vvb>;
using vvvvb = vector<vvvb>;
using vd = vector<double>;
using vvd = vector<vd>;
using vvvd = vector<vvd>;
using vvvvd = vector<vvvd>;
using vvvvvd = vector<vvvvd>;
#define all(A) A.begin(),A.end()
#define ALL(A) A.begin(),A.end()
#define rep(i, n) for (ll i = 0; i < (ll) (n); i++)
using pqr = priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>>;
#define tN(t) (t==1?XN:YN)
#define tS(t) (t==1?XS:YS)
#define tA(t) (t==1?XA:YA)

template<class T>
bool chmax(T& p, T q, bool C = 1) {
    if (C == 0 && p == q) {
        return 1;
    }
    if (p < q) {
        p = q;
        return 1;
    }
    else {
        return 0;
    }
}

template<class T>
bool chmin(T& p, T q, bool C = 1) {
    if (C == 0 && p == q) {
        return 1;
    }
    if (p > q) {
        p = q;
        return 1;
    }
    else {
        return 0;
    }
}

ll gcd(ll(a), ll(b)) {
    if (b == 0)return a;
    ll c = a;
    while (a % b != 0) {
        c = a % b;
        a = b;
        b = c;
    }
    return b;
}

vector<ll> fact, factinv, inv;
ll mod = 998244353;
void prenCkModp(ll n) {
    fact.resize(n + 5);
    factinv.resize(n + 5);
    inv.resize(n + 5);
    fact.at(0) = fact.at(1) = 1;
    factinv.at(0) = factinv.at(1) = 1;
    inv.at(1) = 1;
    for (ll i = 2; i < n + 5; i++) {
        fact.at(i) = (fact.at(i - 1) * i) % mod;
        inv.at(i) = mod - (inv.at(mod % i) * (mod / i)) % mod;
        factinv.at(i) = (factinv.at(i - 1) * inv.at(i)) % mod;
    }

}
ll nCk(ll n, ll k) {
    if (n < k) return 0;
    return fact.at(n) * (factinv.at(k) * factinv.at(n - k) % mod) % mod;
}



/*
ll modPow(long long a, long long n, long long p) {
    if (n == 0) return 1; // 0乗にも対応する場合
    if (n == 1) return a % p;
    if (n % 2 == 1) return (a * modPow(a, n - 1, p)) % p;
    long long t = modPow(a, n / 2, p);
    return (t * t) % p;
}*/


ll modPow(ll a, ll n, ll p) {
    ll res = 1;
    ll k = a;
    while (n > 0) {
        if (n % 2 == 1) {
            res *= k;
            if (res > p)res %= p;
        }
        k = k * k;
        if (k > p)k %= p;
        n /= 2;
    }
    return res;
}


int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    ll N;
    cin>>N;
    vll A(N);
    rep(i,N)cin>>A[i];
    if(N>16){
        cout<<(1<<16)-1<<endl;
        return 0;
    }
    vvb DP(N+1,vb(1<<16,false));
    DP[0][0]=1;
    rep(i,N){
        rep(bit,1<<16){
            if(!DP[i][bit])continue;
            rep(k,16){
                DP[i+1][bit|A[i]]=1;
                A[i]=A[i]/2+(1<<15)*(A[i]%2);
            }
        }
    }
    for(ll i=(1<<16)-1;i>=0;i--){
        if(DP[N][i]){
            cout<<i<<endl;
            return 0;
        }
    }
}