#include<bits/stdc++.h>
using namespace std;
const int MAXN = 1e6+5;
int C[MAXN],siz[MAXN],n,k,ans,mi[MAXN];
vector <int> e[MAXN];
bool cut[MAXN];
void dfs(int p,int fa)
{
    siz[p]=C[p];mi[p]=2*n;
    for(int v:e[p])
    {
        if(v!=fa)
        {
            dfs(v,p);
            if(!cut[v])
            {
                siz[p]+=siz[v];
                if(C[v]==1) mi[p]=min(mi[p],mi[v]);
            }
        }
    }
    if(C[p]==1) mi[p]=min(mi[p],siz[p]);
    if((siz[p]>=k&&((siz[p]%2==k%2)||(siz[p]%2!=k%2&&siz[p]-k>=mi[p])))||siz[p]==k)
    {
        ++ans;
        cut[p]=1;
    }
}
int main()
{
    int T;scanf("%d",&T);
    while(T--)
    {
        scanf("%d %d",&n,&k);ans=0;
        for(int i=1;i<=n;++i) e[i].clear(),cut[i]=0;
        for(int i=1;i<=n;++i) scanf("%d",&C[i]);
        for(int i=1;i<n;++i)
        {
            int u,v;
            scanf("%d %d",&u,&v);
            e[u].push_back(v);
            e[v].push_back(u);
        }
        dfs(1,0);
        printf("%d\n",ans);
    }
    return 0;
}