#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
 
ifstream fin("asmax.in");
ofstream fout("asmax.out");
 
int s;
vector < vector < int > > adj;
vector < int > visited, vals;
 
int asmax(int nod, int &sum_max)
{
    int sum = vals[nod];
    visited[nod] = 1;
 
    for(int i = 0; i < adj[nod].size(); ++i)
    {
        int vecin = adj[nod][i];
 
        if(visited[vecin] == 0)
        {
            int res = asmax(vecin, sum_max);
            if(sum + res > sum) 
                sum = sum + res;
        }
    }
 
    if(sum > sum_max) sum_max = sum;
 
    return sum;
}
 
void solve(int n)
{
    fin>>n;
 
    adj.resize(n + 1);
    visited.resize(n + 1, 0);
    vals.resize(n + 1);
 
    for(int i = 1; i <= n; ++i)
        fin >> vals[i];
 
    for(int i = 1; i < n; ++i)
    {
        int x,y;
        fin >> x >> y;
 
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
 
    s = -1005;
 
    int res = asmax(1, s);
 
    fout << s;
}
 
int main()
{
    int n;
    fin>>n;
    solve(n);
    return 0;
}