#include <bits/stdc++.h>
#define rep(i, n) for (long long i = 0; i < (int)(n); i++)
#define put(i) cout << fixed << i << endl
using namespace std;
using ll = long long;

int main() {
    ll n;
    cin >> n;
    ll ans, maxa = 0;
    vector<ll> a(n), b(n - 1);
    rep(i, n) cin >> a[i];

    map<vector<ll>, ll> mp;
    do {
        for (long long i = 0; i < n - 1; i++) {
            b[i] = a[i] xor a[i + 1];
        }

        ans = b[0];
        for (long long i = 1; i < n - 1; i++) {
            ans = ans xor b[i];
        }
        maxa = max(ans, maxa);
        // mp.at(a) = mp.size();
    } while (next_permutation(a.begin(), a.end()));

    put(maxa);
}