#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
#define rep(i, a, b) for(ll i = a; i < b; ++i)
#define rrep(i, a, b) for(ll i = a; i >= b; --i)
constexpr ll inf = 4e18;
struct SetupIO {
    SetupIO() {
        ios::sync_with_stdio(0);
        cin.tie(0);
        cout << fixed << setprecision(30);
    }
} setup_io;
int main(void) {
    int n;
    cin >> n;
    if(n >= 16) {
        cout << (1 << 16) - 1 << '\n';
        return 0;
    }
    vector<int> a(n);
    rep(i, 0, n) {
        cin >> a[i];
    }
    vector<vector<bool>> dp(n + 1, vector<bool>(1 << 16, false));
    dp[0][0] = true;
    rep(i, 0, n) {
        rep(j, 0, 1 << 16) {
            rep(k, 0, 16) {
                dp[i + 1][j] = dp[i + 1][j] | dp[i][j];
                dp[i + 1][j | a[i]] = dp[i + 1][j | a[i]] | dp[i][j];
                a[i] = (a[i] >> 1) + (1 << 15) * (a[i] & 1);
            }
        }
    }
    int ans = 0;
    rep(i, 0, 1 << 16) {
        if(dp[n][i]) ans = i;
    }
    cout << ans << '\n';
}