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

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
#define rep3(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep2(i, a, b) rep3(i, a, b, 1)
#define rep1(i, n) rep2(i, 0, n)
#define rep0(n) rep1(aaaaa, n)
#define ov4(a, b, c, d, name, ...) name
#define rep(...) ov4(__VA_ARGS__, rep3, rep2, rep1, rep0)(__VA_ARGS__)
#define per(i, a, b) for (ll i = (a) - 1; i >= (b); i--)
#define fore(e, v) for (auto &&e : v)
#define all(a) begin(a), end(a)
#define sz(a) (int)(size(a))
#define lb(v, x) (lower_bound(all(v), x) - begin(v))
#define eb emplace_back

template <typename T, typename S> bool chmin(T &a, const S &b) {
  return a > b ? a = b, 1 : 0;
}
template <typename T, typename S> bool chmax(T &a, const S &b) {
  return a < b ? a = b, 1 : 0;
}
const int INF = 1e9 + 100;
const ll INFL = 3e18 + 100;
#define i128 __int128_t
struct _ {
  _() { cin.tie(0)->sync_with_stdio(0), cout.tie(0); }
} __;
void solve();
int main() {
  int T;
  cin >> T;
  rep(T) solve();
}
void solve() {
  ll N, K;
  cin >> N >> K;
  vl A(N), B(N), C(N), D(N);
  fore(i, A) cin >> i;
  fore(i, B) cin >> i;
  fore(i, C) cin >> i;
  fore(i, D) cin >> i;
  multiset<pll> cnt;
  ll ctr = 0, ans = 0;
  rep(i, N) {
    cnt.insert(pll{A[i], B[i]});
    ctr += B[i];
    ll X = D[i];
    while (X > 0 && (*cnt.begin()).first < C[i]) {
      auto [c, d] = *cnt.begin();
      cnt.erase(cnt.begin());
      if (d <= X) {
        ans += (C[i] - c) * d;
        cnt.insert(pll{C[i], d});
        X -= d;
      } else {
        ans += (C[i] - c) * X;
        cnt.insert(pll{c, d - X});
        cnt.insert(pll{C[i], X});
        X = 0;
      }
    }
    while (ctr > K) {
      auto [c, d] = *prev(cnt.end());
      cnt.erase(prev(cnt.end()));
      ctr -= d;
      if (ctr < K) {
        ll x = K - ctr;
        ctr += x;
        cnt.insert(pll{c, x});
      }
    }
  }
  cout << ans << '\n';
}