#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, temp;
  cin >> n;
  int *a = new int[n + 1];
  a[0] = 0;
  for (int i = 1; i <= n; i++) {
    cin >> temp;
    a[i] = a[i - 1] ^ temp;
  }
  int _max = 0;
  for (int i = 0; i <= n; i++) {
    for (int j = 0; j <= i; j++) {
      if (_max < (a[i] ^ a[j])) {
        _max = a[i] ^ a[j];
      }
    }
  }
  delete[] a;
  cout << _max;
  return 0;
}
