#include <bits/stdc++.h>
using namespace std;
int n, A[200], B[200], maxi;
int main() {
  maxi = 0;
  cin >> n;
  for (long long(i) = (0); (i) < (n); (i)++) {
    cin >> A[i];
    B[i] = A[i];
    if (i != 0) B[i] = B[i] ^ B[i - 1];
    maxi = max(maxi, B[i]);
    maxi = max(maxi, A[i]);
  }
  for (long long(i) = (0); (i) < (n); (i)++) {
    for (long long(j) = (i); (j) < (n); (j)++) {
      int val = B[j] ^ B[i];
      maxi = max(maxi, val);
    }
  }
  cout << maxi << endl;
}
