#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, tmp, xor_sum, i, j;
  cin >> n >> xor_sum;
  vector<int> arr({0});
  arr.push_back(xor_sum);
  for (i = 1; i < n; ++i) {
    cin >> tmp;
    xor_sum = xor_sum ^ tmp;
    arr.push_back(xor_sum);
  }
  int max = arr[1], cur;
  for (i = 1; i < n + 1; ++i) {
    for (j = i; j < n + 1; ++j) {
      cur = arr[j] ^ arr[i - 1];
      if (cur > max) max = cur;
    }
  }
  cout << max;
  return 0;
}
