import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class Main {
	static int n;
	static int[] a, b;
	static List<List<Integer>> list;
	static long[] dp0, dp1;

	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		n = Integer.parseInt(br.readLine());

		String[] sa = br.readLine().split(" ");
		a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = Integer.parseInt(sa[i]);
		}

		sa = br.readLine().split(" ");
		b = new int[n];
		for (int i = 0; i < n; i++) {
			b[i] = Integer.parseInt(sa[i]);
		}

		list = new ArrayList<>(n);
		for (int i = 0; i < n; i++) {
			list.add(new ArrayList<>());
		}
		for (int i = 0; i < n - 1; i++) {
			sa = br.readLine().split(" ");
			int u = Integer.parseInt(sa[0]) - 1;
			int v = Integer.parseInt(sa[1]) - 1;
			list.get(u).add(v);
			list.get(v).add(u);
		}
		br.close();

		dp0 = new long[n];
		dp1 = new long[n];
		dfs(0, -1);
		System.out.println(Math.max(dp0[0], dp1[0]));
	}

	static void dfs(int cur, int p) {
		for (int next : list.get(cur)) {
			if (next == p) {
				continue;
			}
			dfs(next, cur);
			dp0[cur] += Math.max(dp0[next], dp1[next]);
			dp1[cur] += Math.max(dp0[next], dp1[next] + b[cur] + b[next]);
		}
		dp0[cur] += a[cur];
	}
}