#include <bits/stdc++.h>
using namespace std;
bool isprime(unsigned long long n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (unsigned long long i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
long long int gcd(long long int a, long long int b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
long long int exp(long long int value, long long int power) {
  long long int result = 1;
  while (power > 0) {
    if (power & 1LL) {
      result *= value;
      result %= 1000000007;
    }
    value *= value;
    value %= 1000000007;
    power /= 2LL;
  }
  return result;
}
long long int lcm(long long n1, long long n2) {
  long long max = (n1 > n2) ? n1 : n2;
  do {
    if (max % n1 == 0 && max % n2 == 0) {
      return max;
    } else
      ++max;
  } while (true);
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int f, cnt, len, p, q, r, t, i, j, k, l, n, m, x, y, z, b, c, s;
  cin >> n;
  long long a[n];
  long long _xor[100000];
  x = 0;
  for (i = 0; i < n; i++) cin >> a[i];
  for (i = 0; i < n; i++) {
    k = a[i];
    _xor[x] = k;
    x += 1;
    for (j = i + 1; j < n; j++) {
      k = k ^ a[j];
      _xor[x] = k;
      x += 1;
    }
  }
  sort(_xor, _xor + x);
  cout << _xor[x - 1];
  return 0;
}
