#include <fstream>
#include <vector>
#define INF -1e9

using namespace std;

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

void dfs (vector<vector<int>> &adj, vector<bool> &visited,
    vector<int> &values, vector<int> &score, int &max_sum, int node) {
    visited[node] = true;
    score[node] = values[node];

    for (int neighbor : adj[node]) {
        if (!visited[neighbor]) {
            dfs(adj, visited, values,
            score, max_sum, neighbor);
            if (score[neighbor] > 0) {
                score[node] += score[neighbor];
            }
        }
    }
    max_sum = max(max_sum, score[node]);
}

int main() {
    int n, max_sum = INF;
    fin >> n;
    vector<vector<int>> adj(n + 1);
    vector<int> values(n + 1);
    vector<bool> visited(n + 1, false);
    vector<int> score(n + 1);
    for (int i = 1; i <= n; ++i) {
        fin >> values[i];
        max_sum = max(max_sum, values[i]);
    }
    for (int i = 1; i <= n; ++i) {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    dfs(adj, visited, values, score, max_sum, 1);

    fout << max_sum << '\n';
    return 0;
}