#include <cstdio>
#include <iostream>
#include <set>
#include <climits>
#include <map>
#include <algorithm>
#include <list>
#include <vector>
#include <utility>
#include <cstdlib>
#include <iomanip>
#include <cstring>
#include <string>

using namespace std;

list<int> e[16001];
int v[16001], dp[16001];

int dfs(int node, int root) {
    dp[node] = v[node];
    for (list<int>::iterator it = e[node].begin(); it != e[node].end(); it++) {
        if ((*it) == root)
            continue;
        dp[node] += dfs((*it), node);
    }

    return ((dp[node] < 0) ? 0 : dp[node]);
}

int main() {
  //  freopen("tt.txt", "r", stdin);
    freopen("asmax.in", "r", stdin);
    freopen("asmax.out", "w", stdout);

    ios::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> v[i];
    }
    for (int i = 1; i < n; i++) {
        int a, b;
        cin >> a >> b;
        e[a].push_back(b);
        e[b].push_back(a);
    }

    dfs(1, 0);

    int ans = INT_MIN;
    for (int i = 1; i <= n; i++) {
        if (dp[i] > ans)
            ans = dp[i];
    }

    cout << ans;

    return 0;
}