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

void Elim(vector<int64_t> &b, int64_t &x) {
    for (int64_t y: b) {
        x = min(x, x ^ y);
    }
}
void Insert(vector<int64_t> &b, int64_t x) {
    Elim(b, x);
    if (x) {
        b.push_back(x);
    }
}

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n;
    cin >> n;
    vector<int64_t> bs;
    int64_t xo = 0;
    for (int i = 0; i < n; i++) {
        int64_t x;
        cin >> x;
        Insert(bs, x);
        xo ^= x;
    }

    int64_t ans = -1e18;
    for (int len = 0; len <= 60; len++) {
        auto B = bs;
        for (int64_t &y: B) y &= (1LL << (len + 1)) - 1;

        int64_t x = (1LL << len) - 1;
        const int64_t val = (1LL << (len + 1)) - 1;
        // cerr << "B = ";
        // for (int64_t &y: B) cerr << y << ',';
        // cerr << endl;
        // cerr << "x = " << x << endl;
        Elim(B, x);
        if (not x) {
            ans = max(ans, xo ^ val);
        }
    }

    cout << ans << '\n';

    return 0;
}