#include <fstream>
#include <vector>

using namespace std;
const int N = 16001;

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

bool fq[N];
int scor[N], val[N], n;
vector <int> a[N];

void dfs(int x)
{
    fq[x] = true;
    scor[x] = val[x];
    for (auto i : a[x])
    {
        if (!fq[i])
        {
            dfs(i);
            if (scor[i] > 0)
                scor[x] += scor[i];
        }
    }
}

int main()
{
    in >> n;

    for (int i = 1; i <= n; i++)
        in >> val[i];

    for (int i = 1; i <= n; i++)
    {
        int ns, nd;
        in >> ns >> nd;
        a[ns].push_back(nd);
        a[nd].push_back(ns);
    }
    dfs(1);
    int maxi = scor[1];
    for (int i = 1; i <= n; i++)
        maxi = max(maxi, scor[i]);
    out << maxi;
    return 0;
}