#include <fstream>
#include <vector>
using namespace std;
int n, x, y;
ifstream cin("asmax.in");
ofstream cout("asmax.out");
vector<vector<int>> graf;
vector<int> v, viz, dp;
void dfs(int node)
{
    viz[node] = 1;
    dp[node] = v[node];
    for(auto next:graf[node])
        if(!viz[next])
        {
            dfs(next);
            dp[node] = max(dp[node], dp[next] + dp[node]);
        }

}
int main()
{
    cin >> n;
    v.resize(n+1);
    viz.resize(n+1);
    dp.resize(n+1);
    graf.assign(n+1, vector<int>());
    for(int i=1; i<=n; i++)
        cin >> v[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;
}