#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 16001;

struct nod {
    int val;
    vector<int> A;
};
nod M[NMAX];

int N, ma;
int dp[NMAX]; /// dp[i] -> suma maxima a subarborelui cu radacina in i;

void dfs(const int& i, const int& t) {
    dp[i] = M[i].val;
    for(const auto& vec: M[i].A)
        if(vec != t) {
            dfs(vec, i);
            dp[i] = max(dp[i], dp[i] + dp[vec]);
        }
    ma = max(dp[i], ma);
}

int main()
{
    in >> N;
    for(int i = 1; i <= N; i++)
        in >> M[i].val;
    int x, y;
    for(int i = 1; i < N; i++) {
        in >> x >> y;
        M[x].A.push_back(y);
        M[y].A.push_back(x);
    }

    dfs(1, 0);

    out << ma << '\n';
    return 0;
}