#include <fstream>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;

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

const int MAXN = 16005;
int n;
int s[MAXN], c[MAXN];
bool f[MAXN];
vector<int> v[MAXN];

void dfs(int k) {

    f[k] = 1;
    for (int i = 0; i < v[k].size(); ++i) {
        if (f[v[k][i]] == 0) {
            dfs(v[k][i]);
            if (c[v[k][i]] > 0) {
                c[k] += c[v[k][i]];
            }
        }
    }

}

int main() {

    fin >> n;
    for (int i = 1; i <= n; ++i) {
        fin >> c[i];
    }
    for (int i = 1; i < n; ++i) {
        int a, b;
        fin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

    dfs(1);

    int sol = c[1];
    for (int i = 2; i <= n; ++i) {
        sol = max(sol, c[i]);
    }
    fout << sol;

    fout.close();
    return 0;
}