#include <fstream>
#include <climits>
#include <vector>
#define DIM 16005
using namespace std;
 
ifstream fin("asmax.in");
ofstream fout("asmax.out");
 
int n, x, y;
int val[DIM], sum[DIM], viz[DIM];
vector <int> L[DIM]; 
int maxim = INT_MIN;
 
void dfs(int node)
{
    viz[node] = 1;  // marcam nodul ca vizitat
    sum[node] = val[node];  // initializam suma pana la nod cu valoarea nodului
    for (int i = 0; i < L[node].size(); i++)  // iteram prin toate nodurile adiacente
    {
        int vecin = L[node][i];  
        if (viz[vecin] == 0)
        {
            dfs(vecin);  // apelam recursiv dfs pentru fiecare vecin
 
            if (sum[node] + sum[vecin] > sum[node])
                sum[node] += sum[vecin];
            
        }
    }
}
 
int main()
{
    fin >> n;
    for (int i = 1; i <= n; i++)
        fin >> val[i];
    for (int i = 1; i < n; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);  // cream matricea de adiacenta
        L[y].push_back(x);
    }
 
    dfs(1);
 
    for (int root = 1; root <= n; root++)
    {
        if (sum[root] > maxim)
        {
            maxim = sum[root];
        }
    }
    fout << maxim;
    return 0;
}