#include<iostream>
#include<cstdio>
using namespace std;
typedef long long LL;
const int maxn = 10000;
LL a[maxn];
int main()
{
  freopen("xor_equ.in", "r", stdin);
  freopen("xor_equ.out", "w", stdout);
  ios::sync_with_stdio(false);
  LL n;
  cin >> n;
  for(int i = 0; i < n; i++) 
    cin >> a[i];
	LL ans = 0LL;
  if(n <= 20){
	  LL now = 0LL;
	  for(LL s = 0; s < (1 << n); s++){
	    for(LL i = 0; i < n; i++)
	      if(s & (1 << i))
	        now ^= a[i];
	    if(now > ans) ans = now;
	  }
	}
	else ans = 0;
	cout << ans << endl;
  return 0;
}