#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <queue>
#include <cmath>
#include <set>
#include <map>
#define fast_io cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
using namespace std;
typedef long long ll;

int n, V[10001];
vector<int> adj[10001];
int dp[10001][2];   //N번 정점이 우수마을 일때/아닐때 최대 주민수
bool visited[10001];

void dfs(int here, int parent){
    visited[here] = true;
    dp[here][0] = 0;
    dp[here][1] = V[here];

    for(int next : adj[here]){
        if(next==parent) continue;
        if(!visited[next]) dfs(next, here);

        dp[here][0] += max(dp[next][1], dp[next][0]);
        dp[here][1] += dp[next][0];
    }
}

int main(){
    fast_io;
    cin >> n;
    for(int i=1;i<=n;i++) cin >> V[i];
    for(int i=1;i<n;i++){
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    dfs(1, 0);
    cout << max(dp[1][0], dp[1][1]);
}