#include <bits/stdc++.h>
using namespace std;
int i, n, j, a[100000];
int ans;
int main() {
  cin >> n;
  for (i = 1; i <= n; i++) cin >> a[i];
  for (i = 2; i <= n; i++) {
    a[i] ^= a[i - 1];
  }
  for (i = 2; i <= n; i++)
    for (j = 1; j <= i - 1; j++) ans = max(ans, a[i] ^ a[j]);
  for (i = 1; i <= n; i++) ans = max(ans, a[i]);
  cout << ans << endl;
}
