#include <bits/stdc++.h>
const int MOD = 1E9 + 7;
const int N = 100000 + 5;
const int dx[] = {-1, 1, 0, 0, -1, -1, 1, 1};
const int dy[] = {0, 0, -1, 1, -1, 1, -1, 1};
using namespace std;
int a[N];
int sum[N];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
    sum[i] = sum[i - 1] ^ a[i];
  }
  int res = 0;
  for (int i = 1; i <= n; i++)
    for (int j = i; j <= n; j++) res = max(res, sum[j] ^ sum[i - 1]);
  printf("%d\n", res);
  return 0;
}
