#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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

vector<int> cost;
vector< vector<int> > ad;
vector<int> maxCost;
int n;

vector<bool> vis;

void Read(){
    int x, y;
    fin >> n;
    cost.resize(n+5);
    vis.resize(n+5);
    maxCost.resize(n+5, 0);
    for(int i = 1; i <= n; ++i){
        fin >> cost[i];
    }
    ad.resize(n+5);
    for(int i = 1; i < n; ++i){
        fin >> x >> y;
        ad[x].push_back(y);
        ad[y].push_back(x);
    }
}

void DFS(int parent, int node){
    vis[node] = 1;
    maxCost[node] = cost[node];
    for(int i = 0; i < ad[node].size(); ++i){
        int w = ad[node][i];
        if(vis[w] == 0)
            DFS(node, w);
        if(maxCost[w] > 0 && w != parent)
            maxCost[node] += maxCost[w];
    }
    if(maxCost[node] < 0)
        maxCost[node] = 0;
}

void Do(){
    DFS(0, 1);
    fout << maxCost[1] << " ";
    /*for(int i = 1; i<=n; ++i)
        cout << maxCost[i] << " ";*/
}

int main()
{
    Read();
    Do();
    return 0;
}