#include <bits/stdc++.h>
#define ll long long
#define for1 (n) for (int i = 1; i <= n; ++i)
#define for0 (n) for (int i = 0; i < n; ++i)
using namespace std;
 
ifstream fin ("asmax.in");
ofstream fout ("asmax.out");
 
const int maxN = 16 * 1e3 + 5;
 
int n, max_path_sum[maxN], max_sum = INT_MIN;
vector<int> edges[maxN];
bitset<16005> visited;
 
void dfs (int node) {
    visited[node] = true;
    if (edges[node].size() == 1 && node != 1) {
        return;
    }
    for (int to: edges[node]) {
        if (visited[edges[node][to]] == false) {
            dfs(edges[node][to]);
            if (max_path_sum[edges[node][to]] > 0) {
                max_path_sum[node] += max_path_sum[edges[node][to]];
            }
        }
    }
}
 
int main() {
    fin.tie(0); fout.tie(0);
    ios::sync_with_stdio(0);
    fin >> n;
    for (int i = 1; i <= n; ++i) {
        fin >> max_path_sum[i];
    }
    for (int i = 1; i < n; ++i) {
        int x, y; fin >> x >> y;
        edges[x].push_back(y);
        edges[y].push_back(x);
    }
    dfs(1);
    for (int i = 1; i <= n; ++i) {
        max_sum = max(max_sum, max_path_sum[i]);
    }
    fout << max_sum;
    return 0;
}