#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,
    dp[NMAX]; /// dp[i] -> suma subarborelui cu radacina in i;
bool v[NMAX];

int dfs(const int& i) {
    dp[i] = M[i].val;
    v[i] = 1;

    for(const auto& vec: M[i].A)
        if(!v[vec]) {
            int c = dfs(vec);

            if(c > 0) dp[i] += dfs(vec);
        }

    return dp[i];
}

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);

    for(int i = 1; i <= N; i++)
        ma = max(dp[i], ma);

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