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.util.*;
import java.io.*;

public class Codeforces {

    static ArrayList<Integer> g[];
    static boolean init[] , ex[];
    
    public static void main(String[] args) throws IOException {
        Reader.init(System.in);
        int n = Reader.nextInt();
        g = new ArrayList[n+1];
        
        for(int i = 0; i <= n; i++)
            g[i] = new ArrayList();
      
        for(int i = 1; i < n; i++){
            int x = Reader.nextInt(), y = Reader.nextInt();
            g[x].add(y);
            g[y].add(x);
        }
        
        
        init = new boolean[n+1];
        ex = new boolean[n+1];
        for(int i = 1; i <= n; i++)
            init[i] = Reader.nextInt() == 1;
        for(int i = 1; i <= n; i++)
            ex[i] = Reader.nextInt() == 1;
    
        DFS(1, 0, 0, 0, 0);
        System.out.println(count);
        System.out.print(ans);
    }
    
    static StringBuilder ans =  new StringBuilder();
    static int count = 0;
    
    static void DFS(int cur, int level, int even, int odd, int p){
        if((level&1) == 1){
            if((odd&1) == 1 && odd > 0)
                init[cur] = !init[cur];
            
            if(init[cur] != ex[cur]){
                odd++;
                ans.append(cur).append('\n');
                count++;
            }
        }
        
        else{
            if((even&1) == 1 && even > 0)
                init[cur] = !init[cur];
            
            if(init[cur] != ex[cur]){
                even++;
                ans.append(cur).append('\n');
                count++;
            }
        }
        
        for(int i = 0; i < g[cur].size(); i++){
            if(g[cur].get(i) != p)
               DFS(g[cur].get(i), level+1, even, odd, cur);
        }
    }
}

class Edge{
    int to;
    int cost;
    
    Edge(int t, int c){
        to = t;
        cost = c;
    }
}
class Reader {

    static BufferedReader reader;
    static StringTokenizer tokenizer;

    public static int pars(String x) {
        int num = 0;
        int i = 0;
        if (x.charAt(0) == '-') {
            i = 1;
        }
        for (; i < x.length(); i++) {
            num = num * 10 + (x.charAt(i) - '0');
        }

        if (x.charAt(0) == '-') {
            return -num;
        }

        return num;
    }

    static void init(InputStream input) {
        reader = new BufferedReader(
                new InputStreamReader(input));
        tokenizer = new StringTokenizer("");
    }

    static void init(FileReader input) {
        reader = new BufferedReader(input);
        tokenizer = new StringTokenizer("");
    }

    static String next() throws IOException {
        while (!tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(
                    reader.readLine());
        }
        return tokenizer.nextToken();
    }

    static int nextInt() throws IOException {
        return pars(next());
    }

    static long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }
}