#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
void solve() {
  int n;
  cin >> n;
  int a[n], pre[n];
  cin >> a[0];
  pre[0] = a[0];
  int res = pre[0];
  for (long long i = 1; i <= n - 1; i++) {
    cin >> a[i];
    pre[i] = pre[i - 1] ^ a[i];
    res = max(res, pre[i]);
  }
  for (long long i = 1; i <= n - 1; i++) {
    for (long long j = 0; j < i; j++) {
      res = max(res, pre[i] ^ pre[j]);
    }
  }
  cout << res;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long test = 1;
  while (test--) solve();
  return 0;
}
