#include <iostream>
#include <fstream>
#include <stack>
#include <queue>
#include <cmath>
#include <algorithm>
#include <set>
#include <cstring>
#include <map>
#include <string>
#include <bitset>
#include <unordered_map>
#include <unordered_set>
#define oo 2000000000
#define MOD 123457
using namespace std;

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

vector<int>l[16001];
int dp[16001], n, v[16001],x, y,viz[16001];

void dfs(int nod)
{
    viz[nod] = 1;
    for (auto next : l[nod])
    {
        if (viz[next] == 0)
        {
            dfs(next);
            if (dp[next] > 0)
                dp[nod] += dp[next];
        }
           
    }
}
int main()
{
    fin >> n;
    for (int i = 1; i <= n; i++)
    {
        fin >> dp[i];
    }
    for (int i = 1; i < n; i++)
    {
        fin >> x >> y;
        l[x].push_back(y);
        l[y].push_back(x);
    }
    dfs(1);
    int maxim =-2e9;
    for (int i = 1; i <= n; i++)
    {
        maxim = max(maxim, dp[i]);
    }
    fout << maxim;

}