#include<cstdio>
#include<vector>
#include<algorithm>
using namespace std;
struct{
	int c,f;
	vector<int>next;
}x[100010];
int d[100010][2]={0},K;
int TREEDP(int rt,int frt,int f){
	if(d[rt][f]!=0)return d[rt][f];
	else{
		int aaa=0;
		d[rt][1]=x[rt].c;d[rt][0]=0;
		for(int i=0;i<x[rt].next.size();i++){
			if(x[rt].next[i]!=frt)aaa+=TREEDP(x[rt].next[i],rt,(f+1)%2);
		}
		d[rt][0]+=aaa;
		d[frt][1]+=aaa;
		return d[rt][f];
	}
}
int main(){
	freopen("profitz.in","r",stdin);
	freopen("profitz.out","w",stdout);
	int n;scanf("%d",&n);
	for(register int i=1;i<=n;i++)
		scanf("%d",&x[i].c);
	for(register int i=1,a,b;i<=n;i++){
		scanf("%d%d",&a,&b);
		x[a].next.push_back(b);
		x[b].next.push_back(a);
	}
	TREEDP(1,0,1);
	TREEDP(1,0,0);
	printf("%d",max(d[1][0],d[1][1]));
	return 0;
}