#include <iostream>
#include <fstream>
#include <vector>

#define maxN 16001

using namespace std;

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

int n, Smax=-1<<30;
bool viz[maxN];
vector <int> v[maxN];

void readData()
{
    int x,y;
    fin>>n;
    for (int i=1; i<=n; ++i)
    {
        fin>>x;
        v[i].push_back(x);
    }
    while (fin>>x>>y)
    {
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

int DFS(int nod)
{
    int Svecin, Snod=v[nod][0];
    viz[nod]=true;
    for (int i=1; i<v[nod].size(); ++i)
        if (!viz[v[nod][i]])
        {
            Svecin=DFS(v[nod][i]);
            Snod+=Svecin;
        }
    if (Snod>Smax) Smax=Snod;
    if (Snod>0) return Snod;
    return 0;
}

int main()
{
    readData();
    DFS(1);
    fout<<Smax;
    return 0;
}