#include <iostream>
#include <vector>
using namespace std;
const int maxn = 6060;
int f[maxn][2], h[maxn], p[maxn], n;
vector<int> g[maxn];
void dfs(int u, int fa) {   // u是当前节点，fa用于指代u的父节点
    f[u][0] = 0;
    f[u][1] = h[u];
    int sz = g[u].size();
    for (int i = 0; i < sz; i ++) {
        int v = g[u][i];
        if (v == fa) continue;
        dfs(v, u);
        f[u][0] += max(f[v][0], f[v][1]);
        f[u][1] += f[v][0];
    }
}
int main() {
    cin >> n;
    for (int i = 1; i <= n; i ++) cin >> h[i];
    for (int i = 1; i < n; i ++) {
        int a, b;
        cin >> a >> b;
        p[a] = b;
        g[b].push_back(a);
    }
    int rt;
    for (int i = 1; i <= n; i ++) {
        if (!p[i]) {
            rt = i;
            break;
        }
    }
    dfs(rt, -1);
    cout << max(f[rt][0], f[rt][1]) << endl;
    return 0;
}