#include <bits/stdc++.h>
using namespace std;
int main() {
  unsigned int a[100];
  unsigned int n, maxValue, i, i2, t, t2;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> a[i];
  }
  i = 0;
  maxValue = a[i];
  while (i < n) {
    t = a[i];
    t2 = t;
    i2 = i;
    while (i2 < n - 1) {
      i2++;
      t2 = t2 ^ a[i2];
      if (t2 > t) {
        t = t2;
      }
    }
    if (maxValue < t) {
      maxValue = t;
    }
    i++;
  }
  cout << endl;
  cout << maxValue;
  return 0;
}
