#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 = 16005;
bitset<MAX_SIZE> isIterated;
int peakCost[MAX_SIZE], sums[MAX_SIZE];
vector<int> graph[MAX_SIZE];
int maxSum = -INT_MAX;

void findMaxSum(int curPoint) {
    sums[curPoint] = peakCost[curPoint];
    isIterated[curPoint] = 1;
    for (int nextPoint : graph[curPoint]) {
        if (isIterated[nextPoint] == 0) {
            findMaxSum(nextPoint);
            if (isIterated[nextPoint] == 1 && sums[nextPoint] > 0) {
                sums[curPoint] += sums[nextPoint];
            }
        }
    }
    maxSum = max(maxSum, sums[curPoint]);
}

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;
}