#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define X first
#define Y second
#define ALL(v) v.begin(), v.end()
#define pb push_back
#define SZ(a) ((int)a.size())

const int INF = 1e9;
const int N = 1e6 + 5;
struct S {
    int ans, s, m;   
};

S operator+(const S &a, const S &b) {
    return {a.ans + b.ans, a.s + b.s, min(a.m, b.m)};
}

int k;
vector<int> v[N];
int c[N];

S dp[N];
void dfs(int now, int f) {
    dp[now] = {0, 0, INF};
    for (int x : v[now])
        if (x != f) {
            dfs(x, now);
            dp[now] = dp[now] + dp[x];
        }
    if (c[now] == 1)
        dp[now].m = min(dp[now].m, dp[now].s);
    dp[now].s += c[now];
    // cerr << now << " " << dp[now].ans << " " << dp[now].s << " " << dp[now].m << endl;
    if (dp[now].s >= k) {
        if ((((dp[now].s ^ k) & 1) == 0 && dp[now].s - dp[now].m <= k)
         || (dp[now].s - dp[now].m) >= k + 1) {
            dp[now].ans++;
            dp[now].s = 0;
            dp[now].m = INF;
         }
    }
}

void solve() {
    int n;
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
        cin >> c[i], v[i].clear();
    for (int i = 1; i < n; i++) {
        int a, b;
        cin >> a >> b;
        v[a].pb(b);
        v[b].pb(a);
    }
    dfs(1, 1);
    cout << dp[1].ans << "\n";
}

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