// what is matter? never mind. 
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2") 
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
#define ull unsigned long long
//#define int long long
using namespace std;
inline int read()
{
    char c=getchar();int x=0;bool f=0;
    for(;!isdigit(c);c=getchar())f^=!(c^45);
    for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
    if(f)x=-x;return x;
}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;
 
#define maxn 2000005
#define inf 0x3f3f3f3f

int n,k,c[maxn],res;
vi e[maxn];

pii dfs(int u,int pa){
	int sum=0,mn=inf;
	for(int v:e[u]){
		if(v==pa)continue;
		pii fv=dfs(v,u);
		sum+=fv.fi;
		mn=min(mn,fv.se);
	}
	sum+=c[u];
	if(c[u]%2)mn=min(mn,sum);
	
	bool ok=0;
	if(sum>=k){
		if(sum%2==k%2) ok=1;
		else if((sum-mn)>=k) ok=1;
	}
	if(ok) sum=0,mn=inf,++res;
	return mkp(sum,mn);
}

void work()
{
	n=read(),k=read();res=0;
	For(i,1,n) e[i].clear();
	
	For(i,1,n)c[i]=read();
	For(i,2,n){
		int u=read(),v=read();
		e[u].pb(v),e[v].pb(u);
	}
	pii qwq=dfs(1,0);
	cout<<res<<"\n";
}

signed main()
{
	int T=read();
	while(T--)work();
	return 0;
}
/*

*/