#include <bits/stdc++.h>
#define cin ci
#define cout co
using namespace std;
ifstream cin("asmax.in");
ofstream cout("asmax.out");
const int INF = 0x3F3F3F;
int n, x, y;
vector<vector<int>> graf;
vector<int> viz, dp;
void dfs(int node)
{
    viz[node] = 1;
    for(auto next:graf[node])
        if(!viz[next])
        {
            dfs(next);
            dp[node] = max(dp[node], dp[node] + dp[next]);
        }
}
int main()
{
    cin >> n;
    graf.assign(n+1, vector<int>());
    viz.resize(n+1);
    dp.resize(n+1);
    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 maxi = -INF;
    for(int i=1; i<=n; i++)
        maxi = max(maxi, dp[i]);
    cout << maxi;
    return 0;
}