#include <algorithm>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <vector>
#define int long long
#define endl '\n'
using namespace std;

const int N = 6010;

int h[N], e[N], ne[N], idx;
int w[N], fa[N];
int f[N][2];
int n, ans;

void add(int a, int b)
{
    e[idx] = b, ne[idx] = h[a], h[a] = idx++;
}

void dfs(int u, int fa)
{
    f[u][1] = w[u];
    for (int i = h[u]; i != -1; i = ne[i])
    {
        int son = e[i];
        if (son == fa)
        {
            continue;
        }
        dfs(son, u);
        f[u][1] += f[son][0];
        f[u][0] += max(f[son][1], f[son][0]);
    }
}

signed main(void)
{
    memset(h, -1, sizeof(h));

    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> w[i];
    }
    for (int i = 1; i <= n - 1; i++)
    {
        int f, s;
        cin >> s >> f;
        add(f, s);
        fa[s] = f;
    }
    int root = 0;
    for (int i = 1; i <= n; i++)
    {
        if (!fa[i])
        {
            root = i;
        }
    }

    dfs(root, 0);
    cout << max(f[root][0], f[root][1]) << endl;
    return 0;
}