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.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.*;
public class Spoj {
	static ArrayList<Integer>[]arr;
	static int [] current,goal,bfs;
	static boolean[]vis;
	static 	Queue<Integer>q =new LinkedList<Integer>();
	static ArrayList<Integer>arr1=new ArrayList<Integer>();
public static void main(String[] args) throws IOException, InterruptedException {
	Scanner sc =new Scanner(System.in);
	PrintWriter pw =new PrintWriter(System.out);
	int n =sc.nextInt();
	arr=new ArrayList[n];
	goal=new int [n];
	vis =new boolean[n];
	current=new int [n];
	for (int i=0;i<n;++i)
		arr[i]=new ArrayList<Integer>();
	int y=n-1;
	while (y-->0) {
		int a=sc.nextInt()-1,b=sc.nextInt()-1;
		arr[a].add(b);
		arr[b].add(a);
	}
	for (int i=0;i<n;++i)
		current[i]=sc.nextInt();
	for (int i=0;i<n;++i)
		goal[i]=sc.nextInt();
	q.add(0);
	bfs =new int [n];
	bfs();
	vis =new boolean[n];
	dfs(0, 0, 0, 0);
	pw.println(arr1.size());
	for (int i : arr1)
		pw.println(i);
	pw.close();
	}
public static void bfs() {
	int in=0;
	while (!q.isEmpty()) {
		int size=q.size();
		while (size-->0) {
			 int a=q.poll();
			vis[a]=true;
			for (int y1 : arr[a])
				if (!vis[y1])
					q.add(y1);
			bfs[in++]=a;
		}	
	}
}
public static void dfs (int s , int even ,int odd ,int level) {
	vis[s]=true;
	if (level%2==0) {
		current[s]=(current[s]+even%2)%2;
		if (goal[s]!=current[s]) {
			arr1.add(s+1);
			++even;
		}
	}
		
	else {
		current[s]=(current[s]+odd%2)%2;
		if (goal[s]!=current[s]) {
			arr1.add(s+1);
			++odd;
			}
	}
	for (int i :arr[s])
		if (!vis[i])
			dfs(i, even, odd, level+1);
}
static class Scanner {
	StringTokenizer stringTokenizer;
	BufferedReader bfBufferedReader;
	public Scanner(InputStream system) {
		bfBufferedReader=new BufferedReader(new InputStreamReader( system));
	}
	 public Scanner(String file) throws Exception {
            bfBufferedReader = new BufferedReader(new FileReader( file));
        }			 
        public String next() throws IOException {
            while (stringTokenizer == null || !stringTokenizer.hasMoreTokens())
                stringTokenizer = new StringTokenizer( bfBufferedReader.readLine());
            return stringTokenizer.nextToken();
        }
 
        public String nextLine() throws IOException {
            return bfBufferedReader.readLine();
        }
 
        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }
 
        public double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }
 
        public char nextChar() throws IOException {
            return next().charAt(0);
        }
 
        public Long nextLong() throws IOException {
            return Long.parseLong(next());
        }
 
        public boolean ready() throws IOException {
            return bfBufferedReader.ready();
        }
 
        public void waitForInput() throws InterruptedException {
            Thread.sleep(3000);
        }
    }
}