#include <fstream>
#include <vector>

#define INF 16000005
#define NMAX 16005

using namespace std;

ifstream f("asmax.in");
ofstream g("asmax.out");

vector <vector <int> > G;

int n , sol = - INF , x , y;
int v[NMAX] , dp[NMAX];

bool c[NMAX];

void dfs(int node);

int main() {
    f >> n;

    G.resize(n + 5);
    for(int i = 1 ; i <= n ; ++i) {
        f >> v[i];
    }

    for(int i = 1 ; i < n ; ++i) {
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    dfs(1);

    g << sol;
    return 0;
}


void dfs(int node) {
    int sum = 0;
    c[node] = 1;

    for(vector <int> :: iterator it = G[node].begin() ; it != G[node].end() ; ++it) {
        if(c[*it] == 0) {
            dfs(*it);
             if(dp[*it] > 0) {
                sum += dp[*it];
            }
        }
    }

    dp[node] = v[node] + sum;
    sol = max(sol , dp[node]);
}