#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,n) for (int i = 0; i < n; i++)
#define rrep(i,n) for (int i = (n) - 1; i >= 0; i--)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
template<class T> bool chmax(T &a, T b){if (a < b){a = b;return true;} else return false;}
template<class T> bool chmin(T &a, T b){if (a > b){a = b;return true;} else return false;}

int n, A[200010];

int shift(int x){
    return x / 2 + (x % 2) * (1 << 15);
}

int main(){
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    cin >> n;
    rep(i, n){
        cin >> A[i];
    }
    if (n >= 16){
        cout << (1 << 16) - 1 << "\n";
    } else{
        vector<vector<bool>> dp(n + 1, vector<bool>(1 << 16));
        dp[0][0] = true;
        rep(i, n){
            rep(j, 1 << 16){
                if (!dp[i][j]){
                    continue;
                }
                int x = A[i];
                rep(k, 16){
                    dp[i + 1][j | x] = true;
                    x = shift(x);
                }
            }
        }
        rrep(i, 1 << 16){
            if (dp[n][i]){
                cout << i << "\n";
                return 0;
            }
        }
    }
}