#include <bits/stdc++.h>
using namespace std;
void inputOutput() {}
bool isprime(long long int n) {
  if (n == 1) return false;
  if (n == 2 || n == 3) return true;
  for (long long int i = 2; i < sqrt(n) + 1; i++)
    if (n % i == 0) return false;
  return true;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  inputOutput();
  long long int n;
  cin >> n;
  long long int arr[n], ans = 0;
  for (long long int i = 0; i < n; i++) cin >> arr[i];
  for (long long int i = 0; i < n; i++) {
    long long int a = arr[i];
    ans = max(ans, a);
    for (long long int j = i + 1; j < n; j++) {
      a ^= arr[j];
      ans = max(a, ans);
    }
  }
  cout << ans;
  cerr << "time elapsed : " << 1.0 * clock() / CLOCKS_PER_SEC << " sec \n";
  return 0;
}
