#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

const int maxn = 16000;
int v[maxn];
vector<int> adj[maxn];
bool visited[maxn];
int ans1 = -1e9;

int dfs(int node) {
    visited[node]  =true;
    int ans = -1e9;
    bool isleaf = true;
    for (int child: adj[node])
        if (!visited[child]) {
            ans = max(ans, dfs(child));
            isleaf = false;
        }
    if (isleaf)
        ans = 0;
    ans += v[node];
    return ans;
}

int main() {
    int n;
    fin >> n;
    for (int i = 0; i < n; i++)
        fin >> v[i];
    for (int i = 1; i < n; i++) {
        int u, v;
        fin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (int i = 0; i < n; i++)
        ans1 = max(ans1, dfs(i));
        fout << ans1;
    return 0;
}