#include<bits/stdc++.h>
using namespace std;

#define endl "\n"
#define LL long long
#define deb(x) cerr<<#x<<" "<<x<<" "
#define dnl    cerr<<endl



const int maxn = 1e6+5;

LL arr[maxn];

const int d=64;
LL basis[d];
int sz;
void insertVector(LL mask)
{
    for(int i=0; i<d; i++)
    {
        if((mask&(1LL<<i))==0)
            continue;
        if(!basis[i])
        {
            basis[i]=mask;
            ++sz;
            return;
        }
        mask^=basis[i];
    }
}

LL possible(int k){
    LL ans = 0;
    for(int i=0;i<k;i++){
//        if((ans&(1LL<<i))>0)continue;
//        if( !basis[i] )return 0;
        ans ^= basis[i];
    }
    LL big = 1LL<<(k);
    if((big&ans) > 0){
        return 0;
        if(!basis[k])return 0;
        ans ^= basis[k];
    }

    for(int i=0;i<k;i++){
        if(((1LL<<i)&ans) > 0)continue;
        return 0;
    }
    return 1;
}


void solve(int cs){
    int n;
    cin>>n;
    LL x = 0;
    for(int i=1;i<=n;i++){
        cin>>arr[i];
        x ^= arr[i];
        insertVector(arr[i]);
    }

//    deb(x);dnl;
    const int dsz = 60;
    LL ans = x;
//    for(int i=0;i<dsz;i++){
//        deb(i);deb(basis[i]);dnl;
//    }
    for(int i=1;i<=dsz;i++){

        LL a = possible(i);
        if(a==0)continue;
        LL cur = x;
//        cur ^= a;
//        LL newval = a+1;
//        cur ^= newval;
        LL di = 1LL<<(i+1);
        di--;
        ans = max(ans,cur^di);
    }

    cout<<ans<<endl;
}

int main(){
    int t;t = 1;
//    cin>>t;
    for(int cs=1;cs<=t;cs++)solve(cs);
}