#include <fstream>
#include <vector>
#include <climits>

using namespace std;

const int Nmax = 16005;

vector <int> V[Nmax];
int max_sum[Nmax], val[Nmax];

void dfs (int node, int father) {
    max_sum[node] = val[node];
    for (int son : V[node]) {
        if (son != father){
            dfs (son, node);
            if (max_sum[son] > 0)
                max_sum[node] += max_sum[son];
        }
    }
}

int main()
{
    ifstream fin("asmax.in");
    ofstream fout("asmax.out");
    
    int n, x, y;
    
    fin >> n;
    
    for (int i = 1; i <= n; i++)
        fin >> val[i];
    
    for (int i = 1; i <= n; i++) {
        fin >> x >> y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    
    dfs (1, 0);
    
    int sol = INT_MIN;
    
    for (int i = 1; i <= n; i++)
        sol = max (sol, max_sum[i]);
        
    fout << sol;

    return 0;
}