#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

ifstream fin("asmax.in");
ofstream fout("asmax.out");

const int NMax = 16000;

vector <int> G[NMax + 5];

int V[NMax + 5], DP[NMax + 5], N, a, b;

void DFS(int Nod, int Tata)
{
    for(int i = 0; i < (int)G[Nod].size(); i++) {
        int Vecin = G[Nod][i];

        if(Vecin != Tata) {
            DFS(Vecin, Nod);

            if(DP[Vecin] > 0) DP[Nod] += DP[Vecin];
        }
    }
}

int main()
{
    fin >> N;

    for(int i = 1; i <= N; i++)
        fin >> V[i], DP[i] = V[i];

    for(int i = 1; i < N; i++) {
        fin >> a >> b;

        G[a].push_back(b);
        G[b].push_back(a);
    }

    DFS(1, 0);

    int maxi = DP[1];

    for(int i = 2; i <= N; i++)
        maxi = max(DP[i], maxi);

    fout << maxi << '\n';

    fin.close();
    fout.close();

    return 0;
}