#include<bits/stdc++.h>
#define Gc() getchar()
#define Me(x,y) memset(x,y,sizeof(x))
#define Mc(x,y) memcpy(x,y,sizeof(x))
#define d(x,y) ((m)*(x-1)+(y))
#define R(n) (rnd()%(n)+1)
#define Pc(x) putchar(x)
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define eb emplace_back
using namespace std;using ll=long long;using db=double;using lb=long db;using ui=unsigned;using ull=unsigned long long;using pii=pair<int,int>;
const int N=1e6+5,M=N*20+5,K=(1<<25)+5,mod=998244353,Mod=mod-1;const db eps=1e-9;const int INF=1e9+7;mt19937 rnd(time(0));
int n,k,c[N],sum[N],f[N];vector<int> S[N];
int cnt;
void dfs(int x,int La){
	sum[x]=c[x];f[x]=-INF;
	for(int i:S[x]) if(i^La){
		dfs(i,x);
		f[x]=max(f[x]+sum[i],f[i]+sum[x]);
		sum[x]+=sum[i];
	}
	if(c[x]==1) f[x]=max(f[x],1);
	if(sum[x]>=k&&(sum[x]-k)%2==0){
		sum[x]=0;f[x]=-INF;cnt++;
	}else if(f[x]>=k){
		sum[x]=0;f[x]=-INF;cnt++;
	}
}
void Solve(){
	int i,j;scanf("%d%d",&n,&k);
	for(i=1;i<=n;i++) scanf("%d",&c[i]);
	for(i=1;i<=n;i++) S[i].clear();
	cnt=0;for(i=1;i<n;i++){
		int x,y;scanf("%d%d",&x,&y);
		S[x].emplace_back(y);S[y].emplace_back(x);
	}
	dfs(1,0);
	printf("%d\n",cnt);
}
int main(){
	int t=1;
	scanf("%d",&t);
	while(t--) Solve();
	cerr<<clock()*1.0/CLOCKS_PER_SEC<<'\n';
}