#include<iostream>
#include<cstdio>
#include<vector>
#include<cmath>
using namespace std;
int fun[6001];
int n;
vector<int>son[6001];
int f[6001][2];
bool vis[6001];
void dfs(int u){
	vis[u]=true;
	for(int i=0;i<son[u].size();++i){
		if(!vis[son[u][i]]){
			dfs(son[u][i]);
			f[u][1]+=f[son[u][i]][0];
			f[u][0]+=max(f[son[u][i]][1],f[son[u][i]][0]);
		}
	}
	return;
}
int main(){
	freopen("monk.in","r",stdin);
	freopen("monk.out","w",stdout);
	cin>>n;
	for(int i=1;i<=n;++i){
		cin>>fun[i];
		f[i][1]=fun[i];
	}
	for(int i=1;i<n;++i){
		int a,b;
		cin>>a>>b;
		son[a].push_back(b);
		son[b].push_back(a);
	}
	dfs(1);
	cout<<max(f[1][0],f[1][1])<<endl;
	return 0;
}