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

using int64 = long long;
using i128 = __int128_t;

static void print_i128(i128 x) {
    if (x == 0) {
        cout << 0 << '\n';
        return;
    }
    string s;
    while (x > 0) {
        s.push_back(char('0' + (int)(x % 10)));
        x /= 10;
    }
    reverse(s.begin(), s.end());
    cout << s << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int T;
    cin >> T;
    while (T--) {
        int N;
        int64 K;
        cin >> N >> K;

        vector<int64> 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];

        // key = sell price, value = count of unmatched future sell slots
        map<int64, int64> mp;
        int64 sz = 0;
        i128 ans = 0;

        for (int i = N - 1; i >= 0; i--) {
            // 1) Add today's sell slots
            mp[C[i]] += D[i];
            sz += D[i];

            // 2) Use today's buys to match highest profitable sell slots
            int64 rem = B[i];
            while (rem > 0 && !mp.empty()) {
                auto it = prev(mp.end()); // largest sell price
                int64 price = it->first;
                int64 cnt = it->second;

                if (price <= A[i]) break; // no positive profit anymore

                int64 take = min(rem, cnt);
                ans += (i128)take * (price - A[i]);

                rem -= take;
                sz -= take;
                it->second -= take;
                if (it->second == 0) mp.erase(it);
            }

            // 3) At most K sell slots can be carried further to the past
            while (sz > K) {
                auto it = mp.begin(); // discard smallest sell prices
                int64 cnt = it->second;
                int64 drop = min<int64>(cnt, sz - K);

                it->second -= drop;
                sz -= drop;
                if (it->second == 0) mp.erase(it);
            }
        }

        print_i128(ans);
    }

    return 0;
}