#include <bits/stdc++.h>

using namespace std;
using LL = long long;
using i128 = __int128;

void solve() {
  int n, k;
  cin >> n >> k;
  vector<int> a(n), b(k);
  for (int &x : a) cin >> x;
  for (int &x : b) cin >> x;
  LL l = 0, r = 1e16, ans = 0;
  auto check = [&](LL x) {
    vector<i128> c(n);
    for (int i = 0; i < n; i++) c[i] = (i128)x * a[i];
    for (int i = k - 1; i >= 0; i--) {
      int las = b[i];
      for (int j = 0; j < n; j++) {
        i128 ned = c[j] >> i;
        if (ned >= las) {
          c[j] -= (i128)las * (1 << i);
          las = 0;
          break;
        }
        else c[j] -= (i128)ned * (1 << i), las -= ned;
      }
      if (las >= n) return true;
      nth_element(c.begin(), c.begin() + las, c.end(), greater<i128>());
      for (int i = 0; i < las; i++) c[i] = 0;
    }
    for (int i = 0; i < n; i++) if (c[i]) return false;
    return true;
  };
  while (l <= r) {
    LL m = (l + r) / 2;
    if (check(m)) ans = m, l = m + 1;
    else r = m - 1;
  }
  cout << ans << '\n';
}

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int T;
  cin >> T;
  while (T--) solve();
  return 0;
}