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

//高速化 
struct ponjuice{ponjuice(){cin.tie(0);ios::sync_with_stdio(0);cout<<fixed<<setprecision(20);}}PonJuice;
//#define endl '\n' //インタラクティブ問題の時は消す

//型
using ll = long long;
using ld = long double;
template<class T>using vc = vector<T>; template<class T>using vvc = vc<vc<T>>; template<class T>using vvvc = vvc<vc<T>>;
using vi = vc<int>;  using vvi = vvc<int>;  using vvvi = vvvc<int>;
using vl = vc<ll>;   using vvl = vvc<ll>;   using vvvl = vvvc<ll>;
using pi = pair<int, int>;  using pl = pair<ll, ll>;
using ull = unsigned ll;
template<class T>using priq = priority_queue<T>;
template<class T>using priqg = priority_queue<T, vc<T>, greater<T>>;

// for文
#define overload4(a, b, c, d, e, ...) e
#define rep1(n)             for(ll i = 0; i < n; i++)
#define rep2(i, n)          for(ll i = 0; i < n; i++)
#define rep3(i, a, b)       for(ll i = a; i < b; i++)
#define rep4(i, a, b, step) for(ll i = a; i < b; i+= step)
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define per1(n)             for(ll i = n-1; i >= 0; i--)
#define per2(i, n)          for(ll i = n-1; i >= 0; i--)
#define per3(i, a, b)       for(ll i = b-1; i >= a; i--)
#define per4(i, a, b, step) for(ll i = b-1; i >= a; i-= step)
#define per(...) overload4(__VA_ARGS__, per4, per3, per2, per1)(__VA_ARGS__)

//関数
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define si(x) (ll)(x).size()
template<class S, class T>inline bool chmax(S& a, T b){return a < b && ( a = b , true);}
template<class S, class T>inline bool chmin(S& a, T b){return a > b && ( a = b , true);}

inline void yes(){cout << "Yes\n";}
inline void no(){cout << "No\n";}
inline void yesno(bool y = true){if(y)yes();else no();}

//定数
constexpr ll mod = 998244353;
constexpr ll minf=-(1<<29);
constexpr ll inf=(1<<29);
constexpr ll MINF=-(1LL<<60);
constexpr ll INF=(1LL<<60);
const int dx[4] ={-1, 0, 1, 0};
const int dy[4] ={ 0, 1, 0,-1};
const int dx8[8] ={-1,-1,-1, 0, 1, 1, 1, 0};
const int dy8[8] ={-1, 0, 1, 1, 1, 0,-1,-1};

void solve();
int main() {
	int t = 1;
    cin >>t;
    while(t--){
        solve();
    }
}

/*
せっかくなので、PPC は全てコメント書きます


なんかむずそう

フローを考えるといい感じにdp的なことすれば良さそう？ちゃんとは考えてないが

i 日目に入荷するならこの値段で何個まであるよみたいなのを安いのから貪欲に持てばいい感じ？
*/

void solve(){
    ll n,k;
    cin >> n >> k;
    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;

    ll sum = 0;
    multiset<array<ll,2>> st;

    rep(i,0,n) {
        // in
        st.insert({a[i], b[i]});
        sum += b[i];

        // out
        ll bought = 0;
        while(d[i] > 0) {
            if(st.size() && st.begin()->at(0) < c[i]) {
                auto tmp = *st.begin();
                ll res = min(tmp[1], d[i]);
                bought += res;
                ans += res * (c[i] - tmp[0]);
                st.erase(st.begin());
                tmp[1] -= res;
                sum -= res;
                d[i] -= res;
                if(tmp[1] != 0) {
                    st.insert(tmp);
                }
            }else {
                break;
            }
        }
        if(bought) {
            st.insert({c[i], bought});
            sum += bought;
        }

        while(sum > k) {
            auto tmp = *st.rbegin();
            st.erase(prev(st.end()));
            ll res = min(tmp[1], sum-k);
            tmp[1] -= res;
            sum -= res;
            if(tmp[1] > 0) {
                st.insert(tmp);
            }
        }
    }

    cout << ans << endl;
}