#include <iostream>
#include <fstream>
#include <vector>
#define MAX 16005

using namespace std;

ifstream fin("asmax.in");
ofstream fout("asmax.out");

int n, dp[MAX];
vector <int> G[MAX];

void dfs(int nod, int dad){

    for(auto it: G[nod]){

        if(it == dad)
            continue;
        dp[nod] = max(dp[nod], dp[nod] + dp[it]);
        dfs(it, nod);
    }
}

int main()
{
    fin >> n;
    for(int i = 1; i <= n; ++i)
        fin >> dp[i];
    for(int i = 1; i !=n; ++i){
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    dfs(1, 0);

    int maxx=-((1<<31)-1);

    for(int i = 1; i <= n; ++i){
        maxx=max(dp[i], maxx);
    }

    fout<<maxx;
    return 0;
}