#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-8;
int dblcmp(double d) {
  if (fabs(d) < eps) return 0;
  return d > eps ? 1 : -1;
}
const double PI = 3.1415926535897932384626433832795;
const double pi = acos(-1.0);
int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, -1, 0, 1};
long long pov(long long a, long long b, long long mod) {
  long long res = 1;
  while (b > 0) {
    if (b % 2) {
      res *= a;
      b--;
    } else {
      b /= 2;
      a *= a;
      ;
    }
    res %= mod;
  }
  return res;
}
int main(int argc, char* argv[]) {
  int n;
  cin >> n;
  unsigned long long res = 0;
  vector<unsigned long long> ar;
  for (int i = 0; i < n; i++) {
    long long t;
    cin >> t;
    ar.push_back(t);
  }
  for (int i = 0; i < n; i++) {
    unsigned long long t = ar[i];
    if (res < t) {
      res = t;
    }
    for (int j = i + 1; j < n; j++) {
      t ^= ar[j];
      if (res < t) {
        res = t;
      }
    }
  }
  cout << res;
  return 0;
}
