#include <bits/stdc++.h>
using namespace std;
inline long long max(long long a, long long b) { return ((a > b) ? a : b); }
inline long long min(long long a, long long b) { return ((a > b) ? b : a); }
inline long long gcd(long long a, long long b) {
  if (b == 0) return a;
  a %= b;
  return gcd(b, a);
}
long long power(long long x, long long y) {
  if (y == 0) return 1;
  long long a = power(x, y / 2);
  if (y % 2 == 0)
    return a * a;
  else
    return x * a * a;
}
long long powermod(long long x, long long ex, long long md) {
  long long ans = 1ll;
  while (ex > 0) {
    if (ex & 1ll) ans = (ans * x) % md;
    ex >>= 1ll;
    x = (x * x) % md;
  }
  return ans;
}
const long long inf = 1e18 + 9;
const long long mod = 1e9 + 7;
const long double PI = acos(-1);
const long double eps = 1e-9;
const long long N = 2e5 + 11;
long long n, t, easy, hard;
long long a[N], b[N], pfx[N], cnteasy[N], cnthard[N];
vector<pair<long long, long long> > v;
void solve() {
  cin >> n >> t >> easy >> hard;
  for (int i = 0; i < n; i++) cin >> b[i + 1];
  for (int i = 0; i < n; i++) cin >> a[i + 1];
  for (int i = 0; i < n; i++) v.push_back(make_pair(a[i + 1], b[i + 1]));
  sort((v).begin(), (v).end());
  for (int i = 0; i < n; i++) {
    if (v[i].second)
      pfx[i + 1] = pfx[i] + hard;
    else
      pfx[i + 1] = pfx[i] + easy;
    cnthard[i + 1] = cnthard[i] + (v[i].second);
    cnteasy[i + 1] = cnteasy[i] + (!v[i].second);
  }
  if (pfx[n] <= t) {
    cout << n << "\n";
  } else {
    long long ans = 0;
    for (long long i = 0; i < n; i++) {
      long long t = v[i].first - 1;
      if (t < 0) continue;
      long long val = i;
      long long tym = pfx[i];
      long long rem = t - tym;
      if (rem >= 0) {
        long long x = min(rem / easy, cnteasy[n] - cnteasy[i]);
        rem -= (x * easy);
        val += x;
        val += min(rem / hard, cnthard[n] - cnthard[i]);
        ans = max(ans, val);
      }
    }
    cout << ans << "\n";
  }
  for (int i = 0; i < n + 1; i++)
    a[i] = b[i] = pfx[i] = cnteasy[i] = cnthard[i] = 0;
  v.clear();
  n = t = easy = hard = 0;
}
int main() {
  {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
  };
  cout << fixed << setprecision(20);
  long long NTC = 1;
  cin >> NTC;
  long long PTC = 0;
  while (PTC++ < NTC) {
    solve();
    cout << "\n";
  }
  cerr << "Time : " << 1000 * ((double)clock()) / (double)CLOCKS_PER_SEC
       << "ms\n";
}
