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

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

int n, v[16001];
int x, y, vec, mxm = -1;
bool viz[16001];

vector <vector <int> > G;

void DFS(int nod)
{
    viz[nod] = true;
    for (int i = 0; i < G[nod].size(); ++i)
    {
        if (!viz[G[nod][i]])
        {
            DFS(G[nod][i]);
            if (v[G[nod][i]] > 0)
                v[nod] += v[G[nod][i]];
        }

    }
}

int main()
{
    is >> n;
    G.resize(n+1);

    for (int i = 1; i <= n; ++i)
        is >> v[i];

    while (is >> x >> y)
    {
        G[x].push_back(y);
        G[y].push_back(x);
    }

    DFS(1);

    for (int i = 1; i <= n; ++i)
        if (v[i] > mxm)
            mxm = v[i];

    os << mxm;


    is.close();
    os.close();
    return 0;
}