#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 16002
#define INF 20000
using namespace std;

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

long long d[NMAX],n,x,y;
int viz[NMAX];
vector<int> a[NMAX];

void dfs(int nod)
{
    viz[nod] = 1;

    for(int i=0;i<a[nod].size();i++)
    {
        if(viz[a[nod][i]] == 0)
        {
            dfs(a[nod][i]);
        }
    }

    for(int i=0;i<a[nod].size() && a[nod].size()>1;i++)
    {
        if(viz[a[nod][i]]==2)
        {
            d[nod] += max(0ll,d[a[nod][i]]);
        }
    }

    viz[nod] = 2;
}

int main()
{
    in >> n;
    for(int i=1;i<=n;i++) in >> d[i];

    for(int i = 0;i<n-1;i++)
    {
        in >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    dfs(1);
    long long m = -INF;

    for(int i=1;i<=n;i++)
    {
       // cout << d[i] << " ";
        m = max(d[i],m);
    }
    out << m;
    return 0;
}