#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=d-1; i>=0; i--)
    {
        if((mask&(1LL<<i))==0)
            continue;
        if(!basis[i])
        {
            basis[i]=mask;
            ++sz;
            return;
        }
        mask^=basis[i];
    }
}

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


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++){
        if(possible(i)){
//            deb(i);dnl;
            LL y = (1LL<<i);
            LL cur = y-1;
            ans = max(ans,x^y^cur);
        }
    }

    cout<<ans<<endl;
}

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