import java.util.*;
 
public class Main {
    static long[] sum;
    static int[] b;
 
    public static void DFS(int node, int parent, List<Integer>[] G) {
 
        long bestChild = 0;
 
        for (int child : G[node]) {
 
            if (child == parent) {
                continue;
            }
 
            DFS(child, node, G);
 
            bestChild = Math.max(bestChild, sum[child]);
        }
 
        sum[node] = b[node] + bestChild;
    }
 
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
 
        int n = scanner.nextInt();
 
        b = new int[n + 1];
        sum = new long[n + 1];
 
        for (int i = 1; i <= n; i++) {
            b[i] = scanner.nextInt();
        }
 
        List<Integer>[] G = new List[n + 1];
 
        for (int i = 0; i <= n; i++) {
            G[i] = new ArrayList<>();
        }
 
        for (int i = 1; i <= n - 1; i++) {
            int u = scanner.nextInt();
            int v = scanner.nextInt();
 
            G[u].add(v);
            G[v].add(u);
        }
 
        DFS(1, 0, G);
 
        long answer = Long.MIN_VALUE;
 
        for (int i = 1; i <= n; i++) {
            answer = Math.max(answer, sum[i]);
        }
 
        System.out.println(answer);
    }
}

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