#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=100000+5;
const ll inf=0x3f3f3f3f3f3f;
struct sdf{
	int to,next;
}eg[2*N];
int head[N],ne=0;
int n;
ll a[N],T;
void add(int x,int y){
	eg[++ne]={y,head[x]};
	head[x]=ne;return ;
}
ll f[N],sz[N];
void dfs1(int pt,int fa){
	for (int i=head[pt];i!=0;i=eg[i].next){
		int v=eg[i].to;
		if (v==fa)continue;
		dfs1(v,pt);
		sz[pt]+=sz[v];
		f[pt]+=f[v]+sz[v];
	}
	sz[pt]+=a[pt];
	return ;
}
void dfs2(int pt,int fa){
	for (int i=head[pt];i!=0;i=eg[i].next){
		int v=eg[i].to;
		if (v==fa)continue;
		f[v]=f[pt]+sz[1]-2*sz[v];
		dfs2(v,pt);
	}
	return ;
}
int main(){
	freopen ("dqzl.in","r",stdin);
	freopen ("dqzl.out","w",stdout);
	scanf("%d%lld",&n,&T);
	for (int i=1;i<=n;i++){
		scanf("%lld",&a[i]);
	}
	for (int i=1;i<n;i++){
		int x,y;scanf("%d%d",&x,&y);
		add(x,y);add(y,x);
	}
	dfs1(1,1);dfs2(1,1);
	ll ans=inf;
	for (int i=1;i<=n;i++)ans=min(ans,f[i]);
	if (ans>T)printf("Poor Van\n");
	else printf("%lld\n",ans);
	return 0;
}