/**
	author:  shobonvip
	created: 2026.04.19 09:05:48
**/

#include<bits/stdc++.h>
using namespace std;

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)
#define all(v) v.begin(), v.end()

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

void solve() {
	int n; ll k;
	cin >> n >> k;
	ll mpsum = 0;
	map<ll,ll> mp;

	vector<ll> 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) {
		mp[- a[i]] += b[i];
		mpsum += b[i];
		while (d[i] > 0) {
			if (mpsum == 0) break;
			auto itr = mp.end();
			itr--;
			if (itr->second == 0) {
				mp.erase(itr);
				continue;
			}
			if (itr->first + c[i] <= 0) {
				break;
			} 
			ll tmp = min(itr->second, d[i]);
			ans += (itr->first + c[i]) * tmp;
			itr->second -= tmp;			
			if (itr->second == 0) {
				mp.erase(itr);
			}
			mp[- c[i]] += tmp;
			d[i] -= tmp;
			continue;
		}

		while (mpsum > k) {
			if (mpsum == 0) break;
			auto itr = mp.begin();
			if (itr->second == 0) {
				mp.erase(itr);
				continue;
			}
			ll tar = min(mpsum - k, itr->second);
			itr->second -= tar;
			mpsum -= tar;
			if (itr->second == 0) {
				mp.erase(itr);
			}
		}
	}

	cout << ans << '\n';

	
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int t; cin >> t;
	while(t--) solve();
}