#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int f[11111]={};
bool kj[33]={};
long long ans=0;
int n;
void gg(int a)
{
	if(a>n)
	{
		long long temp=0;
		for(int i=1;i<=n;i++)
			if(kj[i])
				temp=temp^f[i];
		if(temp>ans)
			ans=temp;
	}
	else
	{
		kj[a]=1;gg(a+1);kj[a]=0;gg(a+1);
	}
}
int main()
{
	freopen("xor_equ.in","r",stdin);
	freopen("xor_equ.out","w",stdout);
	cin>>n;
	for(int i=1;i<=n;i++)
		cin>>f[i];
	if(n<23)
	gg(1);
	else
	{
		sort(f+1,f+n+1);
		ans=f[n];
		for(int i=n-1;i>=1;i--)
			if(ans<(ans^f[i]))
				ans=ans^f[i];
	}
	cout<<ans<<endl;
}