#include <bits/stdc++.h>
using namespace std;

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

int n, val[16002], s;
vector<int> G[16002];
int cnt, t1[16002], t2[16002], smax = -1e9;
bitset<16002> viz;

void DFS(int x)
{
    viz[x] = true;
    s += val[x];
    smax = max(smax, s);
    for(int w : G[x])
        if(!viz[w]) DFS(w);
}

int main()
{
    int i, j;
    fin >> n;
    for(i = 1; i <= n; i++)
        fin >> val[i];
    for(int t = 1; t < n; t++)
    {
        fin >> i >> j;
        G[i].push_back(j);
    }
    for(i = 1; i <= n; i++)
    {
        viz.reset();
        s = 0;
        DFS(i);
    }
    fout << smax;
    return 0;
}