#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
typedef long long LL;
const int N = 1e5 + 5;

vector<int> G[N];
int w[N];

LL dfs(int u, int father)
{
    LL res = w[u];
    for (int i = 0; i < G[u].size(); ++i)
    {
        int v = G[u][i];
        if (v == father) 
            continue;
        LL tmp = dfs(v, u);
        if (tmp > 0)
            res += tmp;
    }
    return res;
}

int main()
{
    int n, root = 1;
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i)
    {
        scanf("%d", &w[i]);
        if (w[root] < w[i])
            root = i;
    }
    for (int i = 0; i < n-1; ++i)
    {
        int u, v;
        scanf("%d %d", &u, &v);
        G[u].push_back(v);
        G[v].push_back(u);
    }
    printf("%lld", dfs(root, -1));
    return 0;
}