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

#define nmax 16005

using namespace std;

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

vector <int> a[nmax];
int v[nmax], viz[nmax], dp[nmax];
int n;

void citire()
{
    f>>n;
    for(int i=1; i<=n; ++i)
    {
        f>>v[i];
    }
    int x, y;
    for(int i=1; i<n; ++i)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

void DFS(int nod, int father)
{
    viz[nod]=1;
    dp[nod]=v[nod];
    for(auto it:a[nod])
    {
        if(it==father) continue;
        DFS(it, nod);
        dp[nod]=max(dp[nod], dp[nod]+dp[it]);
    }
    viz[nod]=0;
}

int main()
{
    citire();
    DFS(1, 0);
    int sol=dp[1];
    for(int i=2; i<=n; i++)
    {
        sol=max(sol, dp[i]);
    }
    g<<sol;
    return 0;
}