#include <bits/stdc++.h>
using namespace std;
typedef  long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<ll> vll;
int inf_int=2e9;
ll inf_ll=2e18;
typedef pair<int,int> pii;
#define pb push_back
const double pi=3.1415926535898;
#define dout if(debug) cout
#define fi first
#define se second
#define sp setprecision
#define sz size()



#define x1 gfgs
#define y1 asd
#define rank asdsad
bool debug=0;
const int maxn=3e5+107;
ll mod=1e9+7;

void solve()
{
   int n,h;
   cin >> n >> h;
   int a[n];
   bool b[n];
   for(int i=0;i<n;i++)
   {
       cin >> a[i];
   }
   for(int i=0;i<n;i++)
   {
       cin >> b[i];
   }
   int ans=0;
   deque<int> q;
   if(b[0]==0)
   {
       b[0]=1;
       ans++;
   }
   ll sum=a[0];
   int cnt=1;
   deque<int> q1;
   q1.push_back(1);
   q.push_back(a[0]);
   for(int i=1;i<n;i++)
   {

       if(sum-q.front()>=h)
       {
           //cout << "vishel "<<" "<<q.front()<< " " << i <<endl;
           sum=sum-q.front();
           cnt=cnt-q1.front();
           q1.pop_front();
           q.pop_front();
           if(cnt==0 && !q.empty())
           {
           //    cout << i << endl;
               ans++;
               q1[q1.sz-1]=1;
               cnt++;
           }
         //  cout<<"1 " << i <<" "<<sum<<" "<<" "<<cnt<<endl;
           i--;
            continue;
       }
       else
       {
           q.push_back(a[i]);
           q1.push_back(b[i]);
           sum+=a[i];
           if(b[i])
           {
               cnt++;
           }
         //  cout<<"2 " << i <<" "<<sum<<" "<<" "<<cnt<<endl;
       }
   }
   while(!q.empty())
   {
        int x=q.front();
        q.pop_front();
        cnt=cnt-q1.front();
        q1.pop_front();
        if(cnt==0 && !q.empty())
        {
         //   cout << x <<endl;
            ans++;
            break;
        }
   }
   cout << ans<<"\n";


}


#define FILE "skyscraper_5_21"
int main()
{

       // freopen("a.txt","r",stdin);
       // freopen("output.txt","w",stdout);

       //  freopen(FILE".in","r",stdin);
      //  freopen(FILE".out","w",stdout);
       if(!debug)
       {
            ios_base::sync_with_stdio(0);
            cin.tie(0);
           cout.tie(0);
       }
        int t=1;
        cin >> t;
        while(t--)
            solve();
        return 0;
}