#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <climits>
#include <bitset>
using namespace std;

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

const int MAX_SIZE = 16000;
bitset<MAX_SIZE + 1> visited;
int peakCost[MAX_SIZE + 1];
vector<int> graph[MAX_SIZE + 1];
int maxSum = -INT_MAX;

void findMaxSum(int current) {
    visited[current] = 1;
    for (int next : graph[current]) {
        if (visited[next] == 0) {
            findMaxSum(next);
            peakCost[current] += max(0, peakCost[next]);
        }
    }
    maxSum = max(maxSum, peakCost[current]);
}

int main() {
    int peaks;
    fin >> peaks;
    for (int i = 1; i <= peaks; ++i) {
        fin >> peakCost[i];
    }
    for (int i = 1; i < peaks; ++i) {
        int start, end;
        fin >> start >> end;
        graph[start].push_back(end);
        graph[end].push_back(start);
    }
    findMaxSum(1);
    fout << maxSum;
    return 0;
}

/*
 5
 -1 1 3 1 -1
 4 1
 1 3
 1 2
 4 5 -> 4
 
 */