#include <bits/stdc++.h>
#define ff first
#define ss second
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int SZ = 1010101;

int n, k, a[SZ], b[SZ], c[SZ];
vector<int> g[SZ];

int ans = 0;
bool dfs(int p, int v) {
	b[v] = a[v];
	c[v] = 1e9;
	for (int x : g[v]) if (p != x) {
		bool f = dfs(v, x);

		if (!f) { // no cut
			b[v] += b[x];
			c[v] = min(c[v], c[x]);
		}
	}

	if (b[v] - c[v] >= k) {
		++ans; return true;
	}
	else {
		if (b[v] >= k && (b[v] - k) % 2 == 0) {
			++ans; return true;
		}
		else {
			if (a[v] == 1) {
				c[v] = min(c[v], b[v]);
			}
			return false;
		}
	}
}
int main() {
	cin.tie(0); ios_base::sync_with_stdio(0);

	int T;
	cin >> T;
	
	while (T--) {
		cin >> n >> k;
		for (int i = 1; i <= n; i++) {
			cin >> a[i];
		}
		for (int i = 0; i < n - 1; i++) {
			int u, v;
			cin >> u >> v;

			g[u].push_back(v);
			g[v].push_back(u);
		}
		dfs(-1, 1);
		cout << ans << '\n';

		for (int i = 1; i <= n; i++) {
			g[i].clear();
			a[i] = b[i] = c[i] = 0;
		}
		ans = 0;
	}
}