#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//using namespace __gnu_pbds;
using namespace std;
/* #pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")*/
typedef long long ll;
const ll MAXK = 3e3 + 5;
const ll MOD = 1e9 + 7;
const ll MODH = 1e9 + 9;
const int MAXLG = 20;
const long double PI = acos(-1);
const ll p = 41;
const long double EPS = 1e-4;
#define x first
#define y second
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
inline ll rand(ll a, ll b) {ll c = rng(); return a+((ll)abs(c))%(b-a+1);}
ll binpowmod(ll a, ll b, ll m) {a %= m;ll res = 1;while (b > 0) {if (b & 1){res = res * a % m;}a = a * a % m;b >>= 1;
 
}return res;}
//typedef tree<ll, null_type, less_equal<ll>, rb_tree_tag,  //less_equal
  //           tree_order_statistics_node_update> oset;
const int MAXN = 2e5 + 5;

int pre[MAXN];

int get(int l,int r)
{
  return pre[r] - pre[l - 1];
}

int main()
{

ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);

int t;
cin >> t;
while(t--)
{
  int n,k;
  cin >> n >> k;
  vector<int> v(n + 1);
  for(int i = 1 ; i <= n ; i++)
  {
    cin >> v[i];
    pre[i] = pre[i - 1] + v[i];
  }

   int ans = 0;
  for(ll Pre_i = 1 ; Pre_i <= n ; Pre_i++)
  {
    ll Suff_Y = Pre_i ^ k;

    if(Suff_Y + Pre_i > n)
       continue;
    
  ans = max(ans , get(1,Pre_i) + get(n - Suff_Y + 1,n));
  ans = max(ans , get(1,Suff_Y) + get(n - Pre_i + 1 , n));
    
  }

  cout << ans << '\n';
 


}

 
}