#include <bits/stdc++.h>
using namespace std;

#ifdef _RUTHEN
#include <debug.hpp>
#else
#define show(...) true
#endif

using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); i++)
template <class T> using V = vector<T>;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int N;
    cin >> N;
    V<int> A(N);
    rep(i, N) cin >> A[i];
    int M = 1 << 16;
    V<int> dp(M);
    dp[0] = 1;
    rep(i, N) {
        V<int> np = dp;
        rep(j, M) {
            if (dp[j]) {
                rep(k, 16) {
                    np[j | A[i]] = 1;
                    A[i] = (A[i] >> 1) + (1 << 15) * (A[i] & 1);
                }
            }
        }
        swap(dp, np);
        if (dp[M - 1]) {
            cout << M - 1 << '\n';
            return 0;
        }
    }
    int ans = 0;
    rep(i, M) ans = max(ans, i * dp[i]);
    cout << ans << '\n';
    return 0;
}