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

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

int n, v[16001];
int x, y, vec;
bool viz[16001];
int maxim = -0x3f3f3f3f;

vector <vector <int> > G;

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

    }
}

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++ )
        maxim = max(maxim, v[i] );
    os << maxim;

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