#include <bits/stdc++.h>
using namespace std;
clock_t start;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
template <typename T>
void _F(const char *name, T arg1) {
  cerr << name << " = " << arg1 << '\n';
}
template <typename T, typename... Args>
void _F(const char *names, T arg1, Args... args) {
  const char *name = strchr(names, ',');
  cerr.write(names, name - names) << " = " << arg1 << '\n';
  _F(name + 2, args...);
}
template <typename T1, typename T2>
istream &operator>>(istream &in, pair<T1, T2> &q) {
  in >> q.F >> q.S;
  return in;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &out, pair<T1, T2> &q) {
  out << q.F << " " << q.S;
  return out;
}
template <typename T1, typename T2>
pair<T1, T2> operator+(pair<T1, T2> p1, pair<T1, T2> p2) {
  return {p1.F + p2.F, p1.S + p2.S};
}
template <typename T1, typename T2>
pair<T1, T2> operator-(pair<T1, T2> p1, pair<T1, T2> p2) {
  return {p1.F - p2.F, p1.S - p2.S};
}
template <typename T1, typename T2>
bool operator<(pair<T1, T2> p1, pair<T1, T2> p2) {
  return p1 < p2;
}
template <typename T>
void Unique(vector<T> &v) {
  sort((v).begin(), (v).end()),
      v.resize(distance(v.begin(), unique((v).begin(), (v).end())));
}
struct Pair {
  long long F, S, d;
  Pair(long long x, long long y) : F(x), S(y) { d = (F - ((F / S / 2) * S)); }
  bool operator<(Pair other) const { return d > other.d; }
};
const long long N = 1e5 + 1;
std::vector<pair<pair<long long, long long>, long long> > g[N];
std::vector<long long> vis(N);
multiset<Pair> st[2];
long long n, s, cur;
void clear(long long n) {
  for (long long i = 0; i <= n; i++) {
    g[i].clear();
    vis[i] = 0;
  }
  st[0].clear();
  st[1].clear();
  cur = 0;
}
long long dfs(long long v, long long w, long long c) {
  vis[v] = 1;
  long long cnt = 0;
  for (auto u : g[v]) {
    if (!vis[u.first.first]) {
      cnt += dfs(u.first.first, u.first.second, u.second);
    }
  }
  if ((long long)((g[v]).size()) == 1) cnt++;
  cur += w * cnt;
  if (c) st[c - 1].insert(Pair(w * cnt, cnt));
  return cnt;
}
Pair upd(Pair p) {
  long long s = p.S;
  long long f = p.F / p.S / 2 * p.S;
  return Pair(f, s);
}
void solve(long long &test) {
  cin >> n >> s;
  long long u, v, w, c;
  for (long long i = 0; i < n - 1; i++) {
    cin >> u >> v >> w >> c;
    g[u].push_back(make_pair(make_pair(v, w), c));
    g[v].push_back(make_pair(make_pair(u, w), c));
  }
  dfs(1, 0, 0);
  long long moves = 0;
  for (long long i = 0; i < 2; i++) {
    st[0].insert(Pair(0, 1));
    st[1].insert(Pair(0, 1));
  }
  while (cur > s) {
    if (cur - (*begin(st[0])).d <= s) {
      moves++;
      break;
    } else {
      Pair p1 = *begin(st[0]);
      st[0].erase(begin(st[0]));
      Pair tmp = upd(p1);
      Pair p2 = *begin(st[0]);
      Pair p3 = *begin(st[1]);
      if (p3.d < p1.d + p2.d || p3.d < tmp.d + p1.d) {
        moves++;
        cur -= p1.d;
        st[0].insert(tmp);
      } else {
        moves += 2;
        st[0].insert(p1);
        cur -= p3.d;
        st[1].erase(begin(st[1]));
        st[1].insert(upd(p3));
      }
    }
  }
  cout << moves << '\n';
  clear(n);
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  start = clock();
  long long t = 1;
  cin >> t;
  cout << fixed << setprecision(2);
  for (long long i = 1; i <= t; ++i) {
    solve(i);
  }
  cerr << (double(clock() - start) / double(CLOCKS_PER_SEC));
  return 0;
}
