#include <bits/stdc++.h>
using namespace std;
int main() {
  unsigned int a[101][101], n;
  scanf("%i", &n);
  for (int i = 0; i < n; ++i) {
    unsigned int tmp;
    scanf("%i", &tmp);
    a[0][i] = tmp;
  }
  unsigned int max = a[0][0];
  for (int i = 0; i < n; ++i) {
    a[1][i] = 0;
    for (int i1 = i; i1 < n; ++i1) {
      a[1][i] ^= a[0][i1];
      if (a[1][i] > max) {
        max = a[1][i];
      }
    }
  }
  printf("%i\n", max);
  return 0;
}
