#include <bits/stdc++.h>

using namespace std;
#define ll long long
#define pii pair<int, int>
#define ld long double
#define all(a) (a).begin(), (a).end()

const int MAXN = 1e6 + 100, INF = 1e9;
vector<int> g[MAXN];
int c[MAXN], sum[MAXN], x[MAXN], y[MAXN], ans[MAXN];

int k;

void dfs(int v, int p = -1) {
    sum[v] = c[v];
    y[v] = x[v] = INF;
    ans[v] = 0;
    for (int u : g[v]) {
        if (u == p) continue;
        dfs(u, v);
        sum[v] += sum[u];
        ans[v] += ans[u];
        y[v] = min(y[v], y[u]);
        x[v] = min(x[v], x[u] + c[v]);
        if (c[u] == 1) {
            x[v] = min(x[v], c[u] + c[v]);
        }
    }
    if (c[v] == 1) {
        y[v] = min(y[v], sum[v]);
    }
    bool can = false;
    if (y[v] == INF) {
        can = (k % 2 == 0 && k <= sum[v]);
    } else if (x[v] == INF) {
        can = (k % 2 == c[v] % 2 && k <= sum[v]);
    } else {
        if (k > sum[v] - y[v]) {
            can = (k <= sum[v] && k % 2 == sum[v] % 2);
        } else if (k < x[v]) {
            can = (k % 2 == c[v] % 2);
        } else {
            can = true;
        }
    }
    if (can) {
        ans[v]++;
        sum[v] = 0;
        x[v] = y[v] = INF;
    }
    /// cerr << v << ": " << ans[v] << " " << 
}

void solve() {
    int n;
    cin >> n >> k;
    for (int i = 0; i < n; ++i) {
        cin >> c[i];
        g[i].clear();
    }
    for (int i = 1; i < n; ++i) {
        int u, v;
        cin >> u >> v;
        u--; v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    dfs(0);
    cout << ans[0] << "\n";
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int tst;
    cin >> tst;
    while (tst--) {
        solve();
    }

    return 0;
}