XOR Sum

/***** TheAnshul *****/

#include<bits/stdc++.h>
#define ll          long long
#define pb          push_back
#define ppb         pop_back
#define endl        '\n'
#define mii         map<ll int,ll int>
#define msi         map<string,ll int>
#define mis         map<ll int, string>
#define rep(i,a,b)    for(ll int i=a;i<b;i++)
#define mpi         map<pair<ll int,ll int>,ll int>
#define pii         pair<ll int,ll int>
#define vi          vector<ll int>
#define vii         vector<pair<ll int, ll int>>
#define vs          vector<string>
#define all(a)      (a).begin(),(a).end()
#define F           first
#define S           second
#define sz(x)       (ll int)x.size()
#define hell        1000000007
#define lbnd        lower_bound
#define ubnd        upper_bound
#define bs          binary_search
#define mp          make_pair
#define what_is(x)  cerr << #x << " is " << x << endl;
using namespace std;
#define N  1000005
ll cnt;
pii trie[N][2];
void reset()
{
    cnt=1;
    rep(i,0,N)
    {
        trie[i][0].F=-1;
        trie[i][0].S=0;
        trie[i][1].S=0;
        trie[i][1].F=-1;
    }
    return;
}
void insert(ll n)
{
    ll p=0;
    while(n!=0)
    {
        if(trie[p][n&1].F!=-1)
        {
            trie[p][n&1].S++;
            p=trie[p][n&1].F;
        }
        else
        {
            trie[p][n&1].S=1;
            trie[p][n&1].F=cnt;
            p=cnt;
            cnt++;
        }
        n/=2;
    }
    return;
}
ll query(ll n)
{
    ll p=0,ans=0;
    while(n!=0)
    {
        ans=ans<<1;
        if(trie[p][!(n&1)].F!=-1)
        {
            ans++;
            p=trie[p][!(n&1)].F;
        }
        else
        {
            p=trie[p][(n&1)].F;
        }
        n/=2;
    }
    return ans;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int TESTS=1;
    cin>>TESTS;
    while(TESTS--)
    {
        reset();
        ll n;
        cin>>n;
        vi v(n);
        ll mx=0;
        rep(i,0,n)
        {
            cin>>v[i];
        }
        rep(i,1,n)
        {
            v[i]^=v[i-1];
            mx=max(v[i],mx);
        }
        rep(i,0,n)
        {
            insert(v[i]);
            mx=max(query(v[i]),mx);
        }
        cout<<mx<<endl;
    }
    return 0;
}