#include <fstream>
#include <vector>
#include <cstring>

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

const int NMAX = 16000;
int d[NMAX + 5], father[NMAX + 5];
vector <int> graph[NMAX + 5];
bool viz[NMAX + 5];
int dp[NMAX + 5];

void dfs(int node)
{
    if(father[node] == 0)
        return;

    if(dp[node] > 0)
        dp[father[node]] += dp[node];

    node = father[node];
}

int main()
{
    int n;
    fin >> n;
    for(int i = 1; i <= n; i++)
        fin >> d[i];

    for(int i = 1; i <= n - 1; i++)
    {
        int a, b;
        fin >> a >> b;

        graph[a].push_back(b);
        graph[b].push_back(a);
    }

    for(int i = 1; i <= n; i++)
    {
        viz[1] = 1;

        for(auto neigh : graph[i])
            if(viz[neigh] == 0)
            {
                father[neigh] = i;
                viz[neigh] = 1;
            }
    }

    memset(viz, 0, sizeof(viz));

    for(int i = 1; i <= n; i++)
        viz[father[i]] = 1;

    for(int i = 1; i <= n; i++)
        if(viz[i] == 0)
        {
            dp[i] = d[i];
            dfs(i);
        }

    int maxim = 0;
    for(int i = 1; i <= n; i++)
        maxim = max(maxim, dp[i]);

    fout << maxim;

    fin.close();
    fout.close();
    return 0;
}