#2 MLE，但是本地测试无问题

#include<cstdio>
#include<algorithm>
#include<iostream>
#include<cmath>
using namespace std;
struct node{
	int nxt,to;
}mp[6001];
int n,start,de,st,topp;
int r[6001],dp[6001],tot[6001],head[6001];
bool coo[6001],vis[6001];
int w[6001][6001];
void add(int u,int v){
	mp[++topp].to = v,mp[topp].nxt = head[u];
	head[u] = topp;
	return ;
}
void dfs(int now,int dep){
	//printf("%d\n",now);
	de = max(de,dep);
	w[dep][++tot[dep]] = now;
	for(int i = head[now];i;i = mp[i].nxt){
		//if(!vis[mp[i].to]){
			//vis[mp[i].to] = 1;
			dfs(mp[i].to,dep + 1);
		//}
	}
	return ;
}
int main(){
	scanf("%d",&n);
	for(int i = 1;i <= n;i++) scanf("%d",&r[i]);
	for(int i = 1;i < n;i++){
		int l,k;
		scanf("%d%d",&l,&k);
		add(k,l);
		vis[l] = 1;
	}
	for(int i = 1;i <= n;i++){
		if(!vis[i]){
			st = i;
			break;
		}
	}
	//printf("%d\n",st);
	dfs(st,1);
	for(int i = de;i >= 1;i--){
		for(int j = 1;j <= tot[de];j++){
			int now = w[i][j],cnt = 0,m = 0;
			dp[now] = r[now];
			for(int k = head[now];k;k = mp[k].nxt){
				if(!coo[mp[k].to]) m += dp[mp[k].to];
				cnt += dp[mp[k].to];
			}
			if(dp[now] + m > cnt){
				dp[now] = dp[now] + m;
				coo[now] = 1;
			}
			else if(cnt >= 0) dp[now] = cnt;
			//printf("i : %d,j : %d\n",i,j);
			//printf("%d:%d\n",now,dp[now]);
		}
	}
	printf("%d",dp[st]);
	return 0;
}