#include<iostream>

#include<cmath>

#include<algorithm>

#include<vector>

#include<cstdio>

#include<cstdlib>

#include<cstring>

#include<string>

using namespace std;

#define maxn 6005

struct node{

   int to,net;

}que[maxn<<];

int head[maxn];

int n;

int dp[maxn][],father[maxn];//dp[i][0]0表示不去，dp[i][1]1表示去了

bool visited[maxn];

int tot=;

void addedge(int u,int v){

    que[tot].to=v;

    que[tot].net=head[u];

    head[u]=tot++;

    que[tot].to=u;

    que[tot].net=head[v];

    head[v]=tot++;

}

void tree_dp(int node)

{

    int i;

    visited[node] = ;

    for(i=head[node]; i!=-; i=que[i].net)

    {

        int v=que[i].to;

        if(!visited[v]&&father[v] == node)//i为下属

        {

            tree_dp(v);//递归调用孩子结点，从叶子结点开始dp

            //关键

        )   dp[node][] += dp[v][];//上司来,下属不来

            dp[node][] +=max(dp[v][],dp[v][]);//上司不来，下属来、不来

        }

    }

}

int main()

{

    int i;

    int f,c,root;

    while(scanf("%d",&n)!=EOF)

    {

        tot=;

        memset(head,-,sizeof(head));

        memset(dp,,sizeof(dp));

        memset(father,,sizeof(father));

        memset(visited,,sizeof(visited));

        for(i=; i<=n; i++)

        {

            scanf("%d",&dp[i][]);

        }

        root = ;//记录父结点

        bool beg = ;

        while (scanf("%d %d",&c,&f),c||f)

        {

            addedge(c,f);

            father[c] = f;

            if( root == c || beg )

            {

                root = f;

            }

        }

        while(father[root])//查找父结点

            root=father[root];

        tree_dp(root);

        int imax=max(dp[root][],dp[root][]);

        printf("%d\n",imax);

    }

    return ;

}