#include<bits/stdc++.h>
using namespace std;
int a[6002][6002],dp[6006][2],w[6006],c[6006];
bool fa[6006];
int n;
void dfs(int r){
	dp[r][1]=w[r];
	for(int i=1;i<=c[r];i++){
		int s=a[r][i];
		dfs(s);
		dp[r][1]+=dp[s][0];
		dp[r][0]+=max(dp[s][0],dp[s][1]);
	}
}
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>w[i];
	}
	for(int i=1;i<n;i++){
		int x,y;
		cin>>x>>y;
		c[y]++;
		a[y][c[y]]=x;
		fa[x]=1;
	}
	int father=1;
	while(fa[father]==1)father++;
	dfs(father);
	cout<<dp[father][1];
	return 0;
}