#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;
const int e=100020;
int f[e]={0},g[e]={0},a[e]={0},link[e]={0};
int n,t=0;
struct qq
{
	int y,next;
}ee[2*e];
void insert(int startt,int endd)
{
	ee[++t].y=endd;ee[t].next=link[startt];
	link[startt]=t;
}
void dfs(int root,int father)
{
	int tempf=0,tempg=0;
	for(int i=link[root];i;i=ee[i].next)
	{
		if(ee[i].y!=father)
		{
			dfs(ee[i].y,root);
			f[root]+=g[ee[i].y];
			g[root]+=max(f[ee[i].y],g[ee[i].y]);
		}	
	}
	f[root]+=a[root];
}
int main()
{
	freopen("profitz.in","r",stdin);freopen("profitz.out","w",stdout);
	cin>>n;
	for(int i=1;i<=n;i++)
		scanf("%d",&a[i]);
	for(int i=1;i<n;i++)
	{
		int xx,yy;
		scanf("%d%d",&xx,&yy);
		insert(xx,yy);
		insert(yy,xx);
	}
	dfs(1,1);
	cout<<max(f[1],g[1]);
	fclose(stdin);fclose(stdout);
	return 0;
}