#include<iostream>

#include<cstring>

#include<cstdlib>

#include<cstdio>

#include<algorithm>

#define ll long long

using namespace std;

const int maxn=, inf=1e9;

struct poi{int nxt[];}tree[maxn*];

int n, ans, tott;

int a[maxn], suml[maxn], sumr[maxn], ansl[maxn], ansr[maxn];

inline void read(int &k)

{

    int f=; k=; char c=getchar();

    while(c<'' || c>'') c=='-'&&(f=-), c=getchar();

    while(c<='' && c>='') k=k*+c-'', c=getchar();

    k*=f;

}

inline int getans(int x)

{

    int ans=, now=;

    for(int i=, y;~i;i--)

    if(tree[now].nxt[(y=(x&(<<i))!=)^])

    ans+=(<<i), now=tree[now].nxt[y^];

    else now=tree[now].nxt[y];

    return ans;

}

inline void insert(int x)

{

    int now=;

    for(int i=, y;~i;i--)

    if(tree[now].nxt[y=(x&(<<i))!=]) now=tree[now].nxt[y];

    else tree[now].nxt[y]=++tott, now=tott;

}

int main()

{

    read(n);

    for(int i=;i<=n;i++) read(a[i]), suml[i]=suml[i-]^a[i];

    for(int i=n;i;i--) sumr[i]=sumr[i+]^a[i];

    insert();

    for(int i=;i<=n;i++) ansl[i]=max(ansl[i-], getans(suml[i])), insert(suml[i]);

    memset(tree, , sizeof(tree)); insert();

    for(int i=n;i;i--) ansr[i]=max(ansr[i+], getans(sumr[i])), insert(sumr[i]);

    for(int i=;i<=n;i++) ans=max(ans, ansl[i]+ansr[i]);

    printf("%d\n", ans);

}