#include <bits/stdc++.h>

using namespace std;
#define ld long double
#define ll long long
#define int ll

int n;
int a[201010];

bool can(int bit) {
    for (int i = 1; i <= n; i++) {
        if (1 & (a[i] >> bit)) {
            return true;
        }
    }

    ll cur = 0;
    for (int i = 1; i <= n; i++) {
        cur += a[i];
        if (1 & (cur >> bit)) {
            return true;
        }
    }
    return false;
}

int32_t main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }

    ll ans = 0;
    for (int bit = 0; bit <= 62; bit++) {
        if (can(bit)) {
            ans ^= (1LL << bit);
        }
    }
    cout << ans << '\n';
    return 0;
}