#include <bits/stdc++.h>
#define int long long
#define cin ci
#define cout co

using namespace std;
ifstream cin("asmax.in");
ofstream cout("asmax.out");
int n, x, y;
vector<int> dp, viz;
vector<vector<int>> graf;
void dfs(int node)
{
    viz[node] = 1;
    for(auto next : graf[node])
        if(!viz[next])
        {
            dfs(next);
            dp[node] = max(dp[node], dp[next] + dp[node]);
        }
}
int32_t main()
{
    cin >> n;
    dp.resize(n + 5);
    viz.assign(n + 5, 0);
    graf.assign(n + 5, vector<int>());
    for(int i = 1; i <= n; i++)
        cin >> dp[i];
    for(int i = 1; i < n; i++)
    {
        cin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    dfs(1);
    int ans = 0;
    for(int i = 1; i <= n; i++)
        ans = max(ans, dp[i]);
    cout << ans;
    return 0;
}