// Coded by hjxddl
#include <bits/stdc++.h>
#define ll long long
#define db double
const int N = 1e6 + 5;
int ans, n, k;
void dfs(int x, int fa, std::vector<int> &c, std::vector<std::vector<int>> &e, std::vector<int> &sum, std::vector<int> &maxx) {
    sum[x] = c[x];
    maxx[x] = 1e9;
    for (int y : e[x]) {
        if (y == fa) continue;
        dfs(y, x, c, e, sum, maxx);
        maxx[x] = std::min(maxx[y], maxx[x]);
        sum[x] += sum[y];
    }
    if (c[x] == 1)
        maxx[x] = std::min(maxx[x], sum[x]);
    if (sum[x] >= k && ((sum[x] & 1) == (k & 1))) {
        ans++;
        sum[x] = 0;
        maxx[x] = 1e9;
    }
    if (sum[x] >= k && ((sum[x] & 1) != (k & 1))) {
        if (sum[x] - maxx[x] >= k) {
            ans++;
            sum[x] = 0;
            maxx[x] = 1e9;
        }
    }
}
void solve() {
    std::cin >> n >> k;
    std::vector<std::vector<int>> e(n + 5);
    std::vector<int> c(n + 5), sum(n + 5), maxx(n + 5);
    for (int i = 1; i <= n; i++)
        std::cin >> c[i];
    for (int i = 1; i < n; i++) {
        int u, v;
        std::cin >> u >> v;
        e[u].push_back(v);
        e[v].push_back(u);
    }
    ans = 0;
    dfs(1, 1, c, e, sum, maxx);
    std::cout << ans << '\n';
}
int main() {
    std::ios::sync_with_stdio(0);
    std::cin.tie(0), std::cout.tie(0);
    int t = 1;
    std::cin >> t;
    while (t--) {
        solve();
    }
    std::cout << std::flush;
}