Problem: Iahub is very proud of his recent discovery, propagating trees. Right now, he invented a new tree, called xor-tree. After this new revolutionary discovery, he invented a game for kids which uses xor-trees.

The game is played on a tree having n nodes, numbered from 1 to n. Each node i has an initial value initi, which is either 0 or 1. The root of the tree is node 1.

One can perform several (possibly, zero) operations on the tree during the game. The only available type of operation is to pick a node x. Right after someone has picked node x, the value of node x flips, the values of sons of x remain the same, the values of sons of sons of x flips, the values of sons of sons of sons of x remain the same and so on.

The goal of the game is to get each node i to have value goali, which can also be only 0 or 1. You need to reach the goal of the game by using minimum number of operations.

Input

The first line contains an integer n (1 ≤ n ≤ 105). Each of the next n - 1 lines contains two integers ui and vi (1 ≤ ui, vi ≤ n; ui ≠ vi) meaning there is an edge between nodes ui and vi. 

The next line contains n integer numbers, the i-th of them corresponds to initi (initi is either 0 or 1). The following line also contains n integer numbers, the i-th number corresponds to goali (goali is either 0 or 1).

Output

In the first line output an integer number cnt, representing the minimal number of operations you perform. Each of the next cnt lines should contain an integer xi, representing that you pick a node xi.

Examples

Input

10
2 1
3 1
4 2
5 1
6 2
7 5
8 6
9 8
10 5
1 0 1 1 0 1 0 1 0 1
1 0 1 0 0 1 1 1 0 1


Output

2
4
7

Solution (in JAVA):

Solution:


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

public class Solution {
	static int n;
	static List<Integer>[] adj;
	static int[] value, target;
	static int[] r;

	public static void main(String[] args) {
		Scanner in = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
		n = in.nextInt();
		adj = getEdges(in, n, n - 1);
		value = getIntArr(in, n);
		target = getIntArr(in, n);
		r = new int[n + 1];
		solve(1, 0, 0, 0);
		int cnt = 0;
		for (int j = 0; j < r.length; j++) {
			cnt += r[j];
		}
		System.out.println(cnt);
		System.out.println(str(r));
		in.close();
	}

	private static void solve(int u, int p, int flip, int flipNext) {
		r[u] = value[u] ^ flip ^ target[u];
		for (int v : adj[u]) {
			if (v != p) {
				solve(v, u, flipNext, r[u] ^ flip);
			}

		}
	}

	static long mod = 1000000007;

	static long add(long a, long b) {
		long r = a + b;
		if (r < 0) {
			r += mod;
		}
		return r % mod;
	}

	static long mul(long a, long b) {
		return (a * b) % mod;
	}

	static int gcd(int a, int b) {
		if (b == 0) {
			return a;
		} else {
			return gcd(b, a % b);
		}
	}

	static String str(List<Integer> a) {
		StringBuilder sb = new StringBuilder();
		for (int i = 0; i < a.size(); i++) {

			sb.append(a.get(i) + " ");
		}
		return sb.toString();
	}

	static String str(int[] a) {
		StringBuilder sb = new StringBuilder();
		for (int i = 1; i < a.length; i++) {
			if (a[i] > 0) {
				sb.append(i + "\n");
			}
		}
		return sb.toString();
	}

	static int[] getIntArr(Scanner in, int size) {
		int[] arr = new int[size + 1];
		for (int i = 1; i <= size; i++) {
			arr[i] = in.nextInt();
		}
		return arr;
	}

	static int[][] getIntArr(Scanner in, int row, int col) {
		int[][] arr = new int[row][];
		for (int i = 0; i < row; i++) {
			arr[i] = getIntArr(in, col);
		}
		return arr;
	}

	static long[] getLongArr(Scanner in, int size) {
		long[] arr = new long[size];
		for (int i = 0; i < size; i++) {
			arr[i] = in.nextLong();
		}
		return arr;
	}

	static long[][] getLongArr(Scanner in, int row, int col) {
		long[][] arr = new long[row][];
		for (int i = 0; i < row; i++) {
			arr[i] = getLongArr(in, col);
		}
		return arr;
	}

	static char[] getCharArr(Scanner in, int size) {
		char[] arr = in.next().toCharArray();
		return arr;
	}

	static char[][] getCharArr(Scanner in, int row, int col) {
		char[][] arr = new char[row][];
		for (int i = 0; i < row; i++) {
			arr[i] = getCharArr(in, col);
		}
		return arr;
	}

	static String[] getStringArr(Scanner in, int size) {
		String[] arr = new String[size];
		for (int i = 0; i < size; i++) {
			arr[i] = in.next();
		}
		return arr;
	}

	static void swap(int[] a, int i, int j) {
		int t = a[i];
		a[i] = a[j];
		a[j] = t;
	}

	static void set(int[][] a, int v) {
		for (int i = 0; i < a.length; i++) {
			for (int j = 0; j < a[i].length; j++) {
				a[i][j] = v;
			}
		}
	}

	static List<Integer>[] getEdges(Scanner in, int n, int size) {
		List<Integer>[] edges = new List[n + 1];
		for (int i = 0; i <= n; i++) {
			edges[i] = new ArrayList<>();
		}
		for (int i = 0; i < size; i++) {
			int from = in.nextInt();
			int to = in.nextInt();
			edges[from].add(to);
			edges[to].add(from);
		}
		return edges;
	}

}