#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
using ll = long long;
using vll = vector<ll>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vvll = vector<vector<ll>>;
const ll inf = 1e16;
const ll md = 1000000007;

int main() {
  int n;
  cin >> n;
  vll a(n);
  rep(i, n) cin >> a[i];
  ll mx = 0LL;
  rep(i, n) mx = max(mx, a[i]);
  while (true) {
    ll nmx=0LL;
    rep(i, n) {
      a[i] = a[i] ^ mx;
      nmx=max(nmx,a[i]);
    }
    if(nmx>=mx) break;
    mx=nmx;
  }
  cout<<mx<<endl;
  return 0;
}