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

void DFS(int src, bool visited[], int subtreeSum[], vector<int> adjList[]);

int main()
{
    int N, i;
    ifstream f("asmax.in");
    f >> N;

    int subtreeSum[N + 1];
    for (i = 1; i <= N; i++)
        f >> subtreeSum[i];

    int x, y;
    vector<int> adjList[N + 1];
    bool visited[N + 1];
    fill(visited + 1, visited + N + 1, false);
    while (f >> x >> y)
    {
        adjList[x].push_back(y);
        adjList[y].push_back(x);
    }
    f.close();

    DFS(x, visited, subtreeSum, adjList);
    ofstream g("asmax.out");
    int maxSum = subtreeSum[1];
    for (i = 2; i <= N; i++)
        if (subtreeSum[i] > maxSum)
            maxSum = subtreeSum[i];
    g << maxSum;
    g.close();
    return 0;
}

void DFS(int src, bool visited[], int subtreeSum[], vector<int> adjList[])
{
    visited[src] = true;

    for (int i = 0; i < adjList[src].size(); i++)
    {
        int neighbor = adjList[src][i];
        if (!visited[neighbor])
        {
            DFS(neighbor, visited, subtreeSum, adjList);
            if (subtreeSum[neighbor] > 0)
                subtreeSum[src] += subtreeSum[neighbor];
        }
    }
}