#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
vector<int> graph[16005];
int vis[16005], v[1005], s[16005];

void dfs(int node)
{
    vis[node] = true;
    s[node] += v[node];
    for (int i = 0; i < graph[node].size(); i++)
    {
        int next = graph[node][i];
        if (!vis[next])
        {
            dfs(next);
            if (v[next] > 0)
                s[node] += v[next];
        }
    }
}

int main()
{
    ifstream fin("asmax.in");
    ofstream fout("asmax.out");
    int n, x, y, rad, maxx = -1005;
    fin >> n;
    for (int i = 1; i <= n; i++)
    {
        fin >> v[i];
    }
    for (int i = 1; i < n; i++)
    {
        fin >> x >> y;
        graph[y].push_back(x);
        graph[x].push_back(y);
    }
    rad = 1;
    dfs(rad);
    for (int i = 1; i <= n; i++)
        maxx = max(maxx, s[i]);
    fout << maxx;
    return 0;
}