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

using namespace std;

vector <int> Muchii[16010];
int n,m = 1,v[16010],viz[16010],grad[16010];

int DFS(int nod)
{
    viz[nod] = 1;
    for(int i = 0; i < Muchii[nod].size(); ++i)
    {
        if(!viz[Muchii[nod][i]])
        {
            grad[nod]--;
            v[nod] += DFS(Muchii[nod][i]);
        }
    }
    if(grad[nod] <= 1)
    {
        if(v[nod] > 0)
            return v[nod];
        else
            return 0;
    }
}

int main()
{
    fstream f("asmax.in", ios::in);
    fstream g("asmax.out", ios::out);
    f>>n;
    for(int i = 1; i <= n; ++i)
        f>>v[i];
    for(int i = 1; i < n; ++i)
    {
        int x,y;
        f>>x>>y;
        grad[x]++;
        grad[y]++;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }


    while(grad[m] == 1 && m < n)
        m++;
    g<<DFS(m);


    return 0;
}