UVALive - 4682

/*H E A D*/
struct Trie{
    int son[maxn<<2][2];
    int b[67],tot;
    void init(){
//      memset(son,0,sizeof son);
        tot=0;
        son[0][0]=son[0][1]=0;
    }
    void insert(ll x){
        int now=0;
        rep(i,0,32) b[i]=(x>>i)&1;
        rrep(i,32,0){
            if(!son[now][b[i]]){
                son[now][b[i]]=++tot;
                son[tot][0]=son[tot][1]=0;
            }
            now=son[now][b[i]];
        }
    }
    ll find(ll x){
        int now=0;
        ll  ans=0;
        rep(i,0,32) b[i]=(x>>i)&1;
        rrep(i,32,0){
            if(son[now][b[i]^1]){
                now=son[now][b[i]^1];
                ans+=1ll<<i;
            }else{
                now=son[now][b[i]];
            }
        }
        return ans;
    }
}trie;
ll a[maxn];
int main(){
    int T=read();
    while(T--){
        int n=read();
        rep(i,1,n) a[i]=read();
        rep(i,2,n) a[i]^=a[i-1];
        trie.init();
        rep(i,1,n) trie.insert(a[i]);
        ll ans=-oo;
        rep(i,0,n) ans=max(ans,trie.find(a[i]));//0->n
        println(ans);
    }
    return 0;
}