#prag\
ma GCC optimize("O3")
#include<cstdio>
#include<cctype>
#define loop(i,j,k) for(int i=j;i<=k;i++)
#define smax(a,b) a>b?a:b
inline void in(int &x){
    x=0;int f=1;char c=getchar();
    while(!isdigit(c)){if(!(c-'-'))f=-1;c=getchar();}
    while (isdigit(c))x=(x<<3)+(x<<1)+(c^48),c=getchar();
    x*=f;
}
inline void out(int x){
    if(!x){putchar('0');return;}
    if(x<0)x=~x+1,putchar('-');
    char c[30]={0};
    while(x)c[++c[0]]=x%10+48,x/=10;
    while(c[0])putchar(c[c[0]--]);
}
const int maxn=10001;
int n,a[maxn],cnt,ans=0;
bool used[maxn];
inline void dfs(int x){
	if(x==n){
		ans=smax(ans,cnt);
		return;
	}
	loop(i,1,n){
		if(!used[i]){
			used[i]=1;cnt^=a[i];ans=smax(ans,cnt);dfs(x+1);cnt^=a[i];used[i]=0;
			//used[i]=1;dfs(x+1);
		}
	}
}
inline int poi(){
	freopen("xor_equ.in","r",stdin);
	freopen("xor_equ.out","w",stdout);
	in(n);
	loop(i,1,n) in(a[i]);
	dfs(0);
	out(ans);
}
int yuudachi=poi();
int main(){;}