// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
using namespace std;

const int NMAX = 16000;
int dp[NMAX + 1];
int v[NMAX + 1];
int niv[NMAX + 1];
vector<int> L[NMAX + 1];
vector<int> A[NMAX + 1];

void dfs(int node, int tata) {
    for(auto fiu : L[node]) {
        if(fiu != tata) {
            niv[fiu] = niv[node] + 1;
            dfs(fiu, node);
        }
    }
}

int main() {
    ifstream cin("asmax.in");
    ofstream cout("asmax.out");
	int n;
    cin >> n;
    for(int i = 1; i <= n; i++) {
        cin >> v[i];
    }
    for(int i = 1; i < n; i++) {
        int x, y;
        cin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    dfs(1, 0);
    int nivmax = 0;
    for(int i = 1; i <= n; i++) {
        nivmax = max(nivmax, niv[i]);
        A[niv[i]].push_back(i);
    }
    for(int nivel = nivmax; nivel >= 0; nivel--) {
        for(auto it : A[nivel]) {
            dp[it] = v[it];
            for(auto vec : L[it]) {
                if(niv[vec] > niv[it]) {
                    dp[it] += max(0, dp[vec]);
                }
            }
        }
    }
    int sol = -1000;
    for(int i = 1; i <= n; i++) {
        sol = max(sol, dp[i]);
    }
    cout << sol;

    
}