#include <bits/stdc++.h>
#define IOS ios_base::sync_with_stdio(0);
#define tie cin.tie(0);
#define mp make_pair
#define ll long long
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define inf 1000000000
#define zeros(x) ( (x ^ (x - 1)) & x )

using namespace std;

int n, x, y, dp[100100], maxx = -1e9;
vector < int > V[100100];
bool viz[100100];

int dfs(int x)
{
    viz[x] = 1;
    for (auto it : V[x])
        if (!viz[it])
        {
            dfs(it);
            if (dp[x] + dp[it] > dp[x]) dp[x] += dp[it];
            maxx = max(maxx, dp[x]);
        }
    return dp[x];
}


int main(){
    IOS tie
    ifstream cin("sate.in");
    ofstream cout("sate.out");
    cin >> n;
    for (int i = 1; i <= n; i++) cin >> dp[i];
    for (int i = 1; i < n; i++)
    {
        cin >> x >> y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    dfs(1);
    cout << maxx;
    cerr << "Fucking time elapsed: " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms" << '\n';
    return 0;
}