#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define pb push_back

#define Yes cout << "Yes\n"
#define No cout << "No\n"
#define YES cout << "YES\n"
#define NO cout << "NO\n"
#define ff first
#define ss second
#define fori(x,y) for(int i=x;i<=(int)(y);++i)
#define forj(x,y) for(int j=x;j<=(int)(y);++j)
#define fork(x,y) for(int k=x;k<=(int)(y);++k)

#define debug(x) cerr << #x << " = " << x << endl

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

ll MOD = 998244353;
ll qpow(ll a,ll p) {ll res=1; while(p) {if (p&1) {res=res*a%MOD;} a=a*a%MOD; p>>=1;} return res;}

const int N = 1e6+7;

int n,k;
vector<int> g[N];
int arr[N];

int ans = 0;
int dp[N], has[N];
void dfs(int u, int fa) {
    dp[u] = arr[u];
    has[u] = 0;
    for (auto v: g[u]) {
        if (v == fa) continue;
        dfs(v, u);
        dp[u] += dp[v];
        has[u] |= has[v];
    }
    if (dp[u]>=k) {
        if ((dp[u]-k)%2 == 0||(dp[u]-k)%2 && has[u]) {
            dp[u] = 0;
            has[u] = 0;
            ans++;
            return;
        }
    }
    has[u] |= arr[u] == 1;
}
void solve() {
    cin >> n >> k;
    ans = 0;
    fori(1, n) {
        cin >> arr[i];
        g[i].clear();
    }
    fori(1, n-1) {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    dfs(1, 0);
    cout << ans << endl;
}

signed main() {
	IOS;
	int t;
	cin >> t;
	while (t--) {
		solve();
	}
	return 0;
}