package yukicoder;

import java.util.ArrayList;
import java.util.Scanner;

public class Main{
	public static void main(String[] args) {
		new Main().solve();
	}

	ArrayList<Integer>[] edges = new ArrayList[50000];
	int[] A;
	// dp[v][A[u]]:頂点vの子頂点uをvにつないだ時の門松列の総数
	int[][] dp = new int[50001][1001];
	int[] num_up = new int[50001];// num_up[v]:頂点vの持つ数字より大きい数を持つ子頂点の数
	int[] num_down = new int[50001];// num_up[v]:頂点vの持つ数字より小さい数を持つ子頂点の数
	int[] sc_down = new int[50001];// sc_up[v]:頂点vの子頂点がvより小さくなるような場合に含める最大の門松列の総数
	int[] sc_up = new int[50001];// sc_down[v]:頂点vの子頂点がvより大きくなるな場合に含める最大の門松列の総数

	int dfs(int cur, int pre) {
		int ret = 0;
		for (int i = 0; i < edges[cur].size(); i++) {
			int u = edges[cur].get(i);
			if (pre != u) {
				ret = Math.max(ret, dfs(u, cur));
				if (A[cur] > A[u]) {
					if (dp[u][A[cur]] >= 0) {
						dp[cur][A[u]] = Math.max(sc_up[u] - dp[u][A[cur]], dp[cur][A[u]]);
					} else {
						dp[cur][A[u]] = Math.max(num_up[u] + sc_up[u], dp[cur][A[u]]);
					}
				} else if (A[cur] < A[u]) {
					if (dp[u][A[cur]] >= 0) {
						dp[cur][A[u]] = Math.max(sc_down[u] - dp[u][A[cur]], dp[cur][A[cur]]);
					} else {
						dp[cur][A[u]] = Math.max(num_down[u] + sc_down[u], dp[cur][A[u]]);
					}
				}
			}
		}
		for (int i = 1; i <= 1000; i++) {
			if (dp[cur][i] >= 0) {
				if (A[cur] > i) {
					num_down[cur]++;
					sc_down[cur] += dp[cur][i];
				} else if (A[cur] < i) {
					num_up[cur]++;
					sc_up[cur] += dp[cur][i];
				}
			}
		}
		sc_down[cur] += num_down[cur] * (num_down[cur] - 1) / 2;
		sc_up[cur] += num_up[cur] * (num_up[cur] - 1) / 2;
		return Math.max(ret, Math.max(sc_down[cur], sc_up[cur]));
	}

	int N;

	void solve() {
		Scanner sc = new Scanner(System.in);
		N = sc.nextInt();
		A = new int[N];
		for (int i = 0; i < 50000; i++)
			edges[i] = new ArrayList<>();
		for (int i = 0; i < dp.length; i++)
			for (int j = 0; j < dp[0].length; j++)
				dp[i][j] = -1;
		for (int i = 0; i < N; i++)
			A[i] = sc.nextInt();
		for (int i = 0; i < N - 1; i++) {
			int x = sc.nextInt() - 1;
			int y = sc.nextInt() - 1;
			edges[x].add(y);
			edges[y].add(x);
		}
		int ret = dfs(0, -1);
		System.out.println(ret);
	}
}