#include <iostream>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include <string>
#include <bitset>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <algorithm>
#include <sstream>
#include <stack>
#include <iomanip>
using namespace std;
#define pb push_back
#define mp make_pair
typedef pair<int,int> pii;
typedef long long ll;
typedef double ld;
typedef vector<int> vi;
#define fi first
#define se second
#define fe first
#define FO(x) {freopen(#x".in","r",stdin);freopen(#x".out","w",stdout);}
#define Edg int M=0,fst[SZ],vb[SZ],nxt[SZ];void ad_de(int a,int b){++M;nxt[M]=fst[a];fst[a]=M;vb[M]=b;}void adde(int a,int b){ad_de(a,b);ad_de(b,a);}
#define Edgc int M=0,fst[SZ],vb[SZ],nxt[SZ],vc[SZ];void ad_de(int a,int b,int c){++M;nxt[M]=fst[a];fst[a]=M;vb[M]=b;vc[M]=c;}void adde(int a,int b,int c){ad_de(a,b,c);ad_de(b,a,c);}
#define es(x,e) (int e=fst[x];e;e=nxt[e])
#define esb(x,e,b) (int e=fst[x],b=vb[e];e;e=nxt[e],b=vb[e])
#define SZ 666666
int T,n,v,a[SZ]; Edg
ll f[SZ],s[SZ];
void dfs(int x,int fa=0)
{
f[x]=s[x]=0;
for esb(x,e,b) if(b!=fa)
{
dfs(b,x); s[x]+=s[b]; f[x]+=f[b];
}
f[x]+=a[x];
f[x]=max(f[x],-(ll)v);
}
void sol()
{
scanf("%d%d",&n,&v); M=0;
for(int i=1;i<=n;++i) fst[i]=0;
for(int i=1;i<=n;++i) scanf("%d",a+i);
for(int i=1,a,b;i<n;++i)
scanf("%d%d",&a,&b),adde(a,b);
dfs(1); printf("%lld\n",f[1]);
}
int main()
{
scanf("%d",&T);
while(T--) sol();
}
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