#include<bits/stdc++.h>

using namespace std;

int n, rs, s, a[16050];
int dp[16050];
vector<int> V[16050];

void DFS(int x, int pr) {
    for (auto it: V[x]) {
        if (it != pr) {
            DFS(it, x);
            if (dp[it] >= 0)
                dp[x] += dp[it];
        }
    }
    dp[x] += a[x];
    rs = max(rs, dp[x]);
}

int main() {
//    ifstream cin("asmax.in");
//    ofstream cout("asmax.out");
    cin >> n;
    for (int i = 1; i <= n; ++i) cin >> a[i], s += a[i];
    for (int i = 1; i < n; ++i) {
        int x, y;
        cin >> x >> y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    rs = s;
    DFS(1, -1);
    cout << rs;

    return 0;
}