#include <iostream>
#include <vector>
#include <fstream>
#define N 16003
using namespace std;

vector <int> vizitat(N, 0);
vector <vector <int>> listaAd;
int suma[N], cost[N];

void dfs(int nodStart)
{
    vizitat[nodStart] = 1;
    suma[nodStart] = cost[nodStart];
    for (int i = 0; i < listaAd[nodStart].size(); i++)
    {
        int nodCurent = listaAd[nodStart][i];
        if (vizitat[nodCurent] == 0)
        {
            dfs(nodCurent);
            if (suma[nodCurent] + suma[nodStart] > suma[nodStart])
                suma[nodStart] = suma[nodStart] + suma[nodCurent];
        }
    }
}

int main()
{
    ifstream fin("asmax.in");
    ofstream fout("asmax.out");
    int n, rez, st, dr;
    fin >> n;
    listaAd = vector <vector <int>> (n + 1);
    for (int i = 1; i <= n; i++)
        fin >> cost[i];
    for (int i = 1; i <= n - 1; i++) ///arborele are n-1 muchii
    {
        fin >> st >> dr;
        listaAd[st].push_back(dr);
        listaAd[dr].push_back(st);
    }
    dfs(1);
    rez = suma[1];
    for (int i = 2; i <= n; i++)
        if (suma[i] > rez)
           rez = suma[i];
    fout << rez;
    fin.close();
    fout.close();
    return 0;
}