#include <fstream>
#include <climits>
#include <vector>
using namespace std;
const int nmax = 16005;
vector<int> v[nmax];
int val[nmax], dp[nmax];

void dfs(int node, int tactu_mare){
    dp[node] = val[node];
    for(int vec: v[node]){
         if(vec != tactu_mare){
            dfs(vec, node);
            if(dp[vec] > 0){
                dp[node] += dp[vec];
            }
         }
    }
}
int main(){
    ifstream f("asmax.in");
    ofstream g("asmax.out");
    int n;
    f >> n;
    for(int i = 1; i <= n; i++){
        f >> val[i];
    }
    for(int i = 1; i <= n; i++){
        int x, y;
        f >> 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, dp[i]);
    }
    g << sol << '\n';
}