import java.util.Arrays;
import java.util.Scanner;

class Main {

        static Main main = new Main();

        public static void main(String[] args) {
            main.process();
        }
     
        int n = 6010; //N名员工
        int[] happy = new int[n]; //员工的快乐指数 H
        int[] head = new int[n]; //
        int[] edge = new int[n];//边
        int[] next = new int[n];//
        int idx = 0;
        int[][] f = new int[n][2];
        boolean[] hasFather = new boolean[n];

        private void process() {
            Scanner in = new Scanner(System.in);
            n = in.nextInt();
            for (int i = 1; i <= n; i++) happy[i] = in.nextInt();
            Arrays.fill(head, -1);
            for (int i = 0; i < n - 1; i++) {
                int a = in.nextInt(), b = in.nextInt();
                add(b, a);
                hasFather[a] = true;
            }
            int root = 1;
            while (hasFather[root]) root++;
            dfs(root);
            System.out.println(Math.max(f[root][0], f[root][1]));
        }

        private void dfs(int u) {
            f[u][1] = happy[u];
            for (int i = head[u]; i != -1; i = next[i]) {
                int j = edge[i];
                dfs(j);
                f[u][1] += f[j][0];
                f[u][0] += Math.max(f[j][1], f[j][0]);
            }


        }

        /**
        	数组表示邻接表
         * @param a father
         * @param b son
         */
        private void add(int a, int b) {
            edge[idx] = b;
            next[idx] = head[a];
            head[a] = idx++;
        }

    }