#include <bits/stdc++.h>
#define cin ci
#define cout co
using namespace std;
ifstream cin("asmax.in");
ofstream cout("asmax.out");
int n;
vector<int> v, dp;
vector<vector<int>> graf;
void dfs(int node, int par)
{
    dp[node] = v[node];
    for(auto next : graf[node])
        if(next != par)
        {
            dfs(next, node);
            dp[node] = max(dp[node], dp[node] + dp[next]);
        }
}
int main()
{
    cin.tie(0);
    ios_base::sync_with_stdio(0);
    cin >> n;
    dp.assign(n + 5, 0);
    v.resize(n + 5);
    graf.assign(n + 5, vector<int>());
    for(int i = 1; i <= n; i++)
        cin >> v[i];
    for(int i = 1; i < n; i ++)
    {
        int x, y;
        cin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    int ans = -1e9;
    dfs(1, 0);
    for(int i = 1; i <= n; i ++)
        ans = max(ans, dp[i]);
    cout << ans;
    return 0;
}