#include <bits/stdc++.h>

using namespace std;

#define TITLE "asmax"
ifstream f (TITLE".in");
ofstream g (TITLE".out");

int answer=-INT_MAX;

dfs(int Node, vector<vector<int>> &Graph, vector<int> &Visited, vector<int> &dp, vector<int> &Values)
{
    Visited[Node]=true;
    for(auto it : Graph[Node])
    {
        if(!Visited[it])
        {
            dfs(it,Graph,Visited,dp,Values);
            if(dp[it]>0)
                dp[Node]+=dp[it];
        }
    }
    dp[Node]=max(dp[Node],Values[Node]);
    answer=max(answer,dp[Node]);
}

int main()
{
    int n;
    vector<int> Values(n+1);
    f>>n;
    for(int i=1; i<=n; i++)
        f>>Values[i];
    vector<vector<int>> Graph(n+1);
    for(int a,b; f>>a>>b; Graph[a].emplace_back(b), Graph[b].emplace_back(a));
    vector<int> Visited(n+1),dp(n+1);
    dp[1]=Values[1];
    dfs(1,Graph,Visited,dp,Values);
    g<<answer;
    return 0;
}