#include <bits/stdc++.h>
using namespace std;
const int N = 150;
int n;
int a[N], b[N];
int main() {
  scanf("%d", &n);
  b[0] = 0;
  for (int i = 1; i <= n; i++) scanf("%d", &a[i]), b[i] = b[i - 1] ^ a[i];
  int mx = -1;
  for (int i = 1; i <= n; i++)
    for (int j = i; j <= n; j++) {
      mx = max(mx, (b[i - 1] ^ b[j]));
    }
  printf("%d\n", mx);
  return 0;
}
