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

using namespace std;

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

const int NMAX = 16003;
vector<int> g[NMAX];
int dp[NMAX], v[NMAX];
bool vis[NMAX];

void dfs(int nod, int parent) {
    dp[nod] = v[nod];
    vis[nod] = true;

    for (auto nxt : g[nod]) {
        if (nxt != parent && !vis[nxt]) {
            dfs(nxt, nod);
            dp[nod] = max(dp[nod], dp[nod] + dp[nxt]);
        }
    }
}

int main() {

    int n;
    fin >> n;
    for (int i = 1; i <= n; i++) {
        fin >> v[i];
    }
    for (int i = 1; i <= n - 1; i++) {
        int x, y;
        fin >> x >> y;

        g[x].push_back(y);
        g[y].push_back(x);
    }

    dfs(1, 0);

    int res = -1e8;
    for (int i = 1; i <= n; i++) {
        res = max(res, dp[i]);
    }

    fout << res;


    return 0;
}