#include <bits/stdc++.h>
using namespace std;
using ll=long long;
const ll ILL=2167167167167167167;
const int INF=2100000000;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using pq_ = priority_queue<T, vector<T>, greater<T>>;
template<class T> int LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> int UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(b<a){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
    if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
    else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(int)(a&1),a>>=1;}return res;}
template<class T> T square(T a){return a * a;}

#include<atcoder/segtree>
ll op(ll a, ll b) {
    return a + b;
}
ll e() {
    return 0;
}

ll target;
bool f(ll x) {
    return target >= x;
}


const int L = 5'000'167;
atcoder::segtree<ll, op, e> seg(L);
void solve();
// DEAR MYSTERIES / TOMOO
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    int N;
    ll K;
    cin >> N >> K;
    vector<int> A(N), B(N), C(N), D(N);
    rep(i, 0, N) cin >> A[i];
    rep(i, 0, N) cin >> B[i];
    rep(i, 0, N) cin >> C[i];
    rep(i, 0, N) cin >> D[i];
    ll ans = 0;
    rep(i, 0, N) {
        seg.set(A[i], seg.get(A[i]) + B[i]);
        int fr = 0;
        ll tmp_sum = 0;
        while (D[i]) {
            target = 0;
            int l = seg.max_right<f>(fr);
            if (l >= C[i]) {
                break;
            }
            ll tmp = min((ll)D[i], seg.get(l));
            ans += (ll)(C[i] - l) * tmp;
            D[i] -= tmp;
            seg.set(l, seg.get(l) - tmp);
            tmp_sum += tmp;
        }
        if (tmp_sum) seg.set(C[i], seg.get(C[i]) + tmp_sum);
        fr = L;
        while (seg.all_prod() > K) {
            target = 0;
            int r = seg.min_left<f>(fr);
            r--;
            ll tmp = min(seg.all_prod() - K, seg.get(r));
            seg.set(r, seg.get(r) - tmp);
            fr = r;
        }
    }
    cout << ans << "\n";
    {
        while (true) {
            int l = seg.max_right<f>(0);
            if (l == L) break;
            seg.set(l, 0);
        }
    }
}