#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;
void solve() {
    int N;
    long long K;
    cin >> N >> K;
    vector<long long> A(N), B(N), C(N), D(N);
    for (int i = 0; i < N; ++i) cin >> A[i];
    for (int i = 0; i < N; ++i) cin >> B[i];
    for (int i = 0; i < N; ++i) cin >> C[i];
    for (int i = 0; i < N; ++i) cin >> D[i];
    map<long long, long long> mp;
    long long sz = 0;
    long long ans = 0;
    for (int i = N - 1; i >= 0; --i) {
        if (D[i] > 0) {
            mp[C[i]] += D[i];
            sz += D[i];
        }
        long long b_rem = B[i];
        long long matched = 0;
        while (b_rem > 0 && !mp.empty()) {
            auto it = mp.end();
            --it;
            long long val = it->first;
            long long cnt = it->second;
            if (val <= A[i]) {
                break;
            }
            long long m = min(b_rem, cnt);
            ans += m * (val - A[i]);
            b_rem -= m;
            matched += m;
            sz -= m;
            it->second -= m;
            if (it->second == 0) {
                mp.erase(it);
            }
        }
        if (matched > 0) {
            mp[A[i]] += matched;
            sz += matched;
        }
        while (sz > K && !mp.empty()) {
            auto it = mp.begin();
            long long exc = sz - K;
            long long m = min(exc, it->second);
            sz -= m;
            it->second -= m;
            if (it->second == 0) {
                mp.erase(it);
            }
        }
    }
    cout << ans << "\n";
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int T;
    if (cin >> T) {
        while (T--) {
            solve();
        }
    }
    return 0;
}