#include <iostream>
#include<vector>
using namespace std;

const int N = 1e4 + 10;
vector<int> tr[N];
int f[N][2], v[N], Happy[N], n;
void dfs(int u)
{
    f[u][0] = 0;
    f[u][1] = Happy[u];
    for (auto v : tr[u]) 
    {
        dfs(v);
        f[u][0] += max(f[v][0], f[v][1]);
        f[u][1] += f[v][0];
    }
}
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n; 
    for (int i = 1; i <= n; ++i)
        cin >> Happy[i];
    for (int i = 1, x, y; i < n; ++i)
    {
        cin >> x >> y; 
        v[x] = 1;
        tr[y].push_back(x);
    }
    int root;
    for (int i = 1; i <= n; ++i)
    {
        if (!v[i])
        {
            root = i;
            break; 
        }
    }
    dfs(root);
    cout << max(f[root][0], f[root][1]) << "\n";
}