#include<stdio.h>
#include<queue>
#include<iostream>
#include<vector>
#include<algorithm>
#define maxn 10050
using namespace std;
typedef long long LL;
LL n,a[maxn],bmax,res;
bool use[maxn];
vector<LL> b[61];
/*int getnum(){
	int tmp=0;
	char c;
	while((c=getchar())!=' '&&c!='\n')    tmp=tmp*10+c-'0';
	return tmp;
}*/
/*int getbit(int x){
	int i=1;
	while(x>>i){
		i++;
	};
	return i;
}*/
void read(){
	scanf("%lld",&n);
	for(int i=1;i<=n;i++){
		scanf("%lld",&a[i]);
//		int bit=getbit(a[i]);
//		b[bit].push_back(a[i]);
//		bmax=max(bmax,bit);
	}
}
void dfs(LL i,LL k,LL nk,LL ans){
	if(k==nk){res=max(ans,res);return;}
	for(int j=i+1;j<=n-(k-nk)+1;j++){
		dfs(j,k,nk+1,ans^a[j]);
	}
}
void solve(){
	for(LL k=1;k<=n;k++){
		for(LL i=1;i<=n-k+1;i++){
			dfs(i,k,1,a[i]);	
		}
	}
}
int main(){
	freopen("xor_equ.in","r",stdin);
	freopen("xor_equ.out","w",stdout);
	read();
	solve();
	printf("%lld",res);
	return 0;
}