#include<cstdio>
#include<cmath>
#include<iostream>
#include<cstring>
#include<algorithm>
#define XLM
using namespace std;
const int maxn=10010;
long long n,val[maxn],ans;


//20
bool choosed[maxn];

void check(){
	long long num=0;
	for (int i=1;i<=n;i++) if (choosed[i]) num^=val[i];
	ans=max(ans,num);
}

void dfs(int pos){
	if (pos==n+1){
		check();return;
	}
	choosed[pos]=1;
	dfs(pos+1);
	choosed[pos]=0;
	dfs(pos+1);
}

void deal_20(){
	dfs(1);
	printf("%lld",ans);
}

int main(){
	#ifdef XLM
	freopen("xor_equ.in","r",stdin);
	freopen("xor_equ.out","w",stdout);
	#endif
	scanf("%lld",&n);
	for (int i=1;i<=n;i++) scanf("%lld",&val[i]);
	deal_20();
}