#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
int a[100005], sum[100005], n, i, j;
;
int main() {
  scanf("%d", &n);
  for (i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
    sum[i] = sum[i - 1] ^ a[i];
  }
  int res = 0;
  for (i = 1; i <= n; i++)
    for (j = i; j <= n; j++) res = max(res, sum[j] ^ sum[i - 1]);
  printf("%d\n", res);
}
