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 javax.print.DocFlavor;
import javax.swing.plaf.basic.BasicInternalFrameTitlePane;
import java.io.*;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.nio.Buffer;
import java.nio.charset.IllegalCharsetNameException;
import java.sql.BatchUpdateException;
import java.util.*;
import java.util.stream.Stream;
import java.util.Vector;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import static java.lang.Math.*;
import java.util.*;
import java.nio.file.StandardOpenOption;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Iterator;
import java.util.PriorityQueue;

public class icpc
{
    static int[] A;
    static int[] B;
    static int count = 0;
    static StringBuilder stringBuilder = new StringBuilder();
    public static void main(String[] args)throws IOException
    {
        Reader in = new Reader();
//        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

        int n = in.nextInt();
        ArrayList<Integer>[] adj = (ArrayList<Integer>[])new ArrayList[n];
        for(int i=0;i<n;i++)
            adj[i] = new ArrayList<>();
        for(int i=0;i<n-1;i++)
        {
            int a = in.nextInt();
            int b = in.nextInt();
            adj[b-1].add(a - 1);
            adj[a-1].add(b - 1);
        }
        A = new int[n];
        B = new int[n];
        for(int i=0;i<n;i++)
            A[i] = in.nextInt();
        for(int i=0;i<n;i++)
            B[i] = in.nextInt();
        DFS(adj);
        System.out.println(count);
        System.out.println(stringBuilder);
    }
    public static void DFS(ArrayList<Integer>[] adj)
    {
        int n = adj.length;
        boolean[] visited = new boolean[n];
        explore(adj, visited, 0, 0, 0, 0, false, false);
    }
    public static void explore(ArrayList<Integer>[] adj, boolean[] visited, int v, int even, int odd, int level, boolean flag1, boolean flag2)
    {
        visited[v] = true;
        int change = even ^ odd;
        if((A[v] != B[v] && change == 0) || (A[v] == B[v] && change == 1))
        {
            if(level % 2 != 0)
            {
                flag1 = true;
                if(odd == 1)
                {
                    odd = 0;
                    flag1 = false;
                }
                else
                    odd = (odd + 1) % 2;
            }
            else
            {
                flag2 = true;
                if(even == 1)
                {
                    even = 0;
                    flag2 = false;
                }
                else
                    even = (even + 1) % 2;
            }
            count++;
            stringBuilder.append(v + 1).append("\n");
        }
        if(flag1)
            odd = (odd + 1) % 2;
        if(flag2)
            even = (even + 1) % 2;
        for(int i=0;i<adj[v].size();i++)
        {
            if(!visited[adj[v].get(i)])
                explore(adj, visited, adj[v].get(i), even, odd,level + 1, flag1, flag2);
        }
        return;
    }
}
class Matrix
{
    long a;
    long b;
    long c;
    long d;

    public Matrix(long a, long b, long c, long d)
    {
        this.a = a;
        this.b = b;
        this.c = c;
        this.d = d;
    }
}
class Game implements Comparable<Game>
{
    long x;
    long y;

    public Game(long x, long y)
    {
        this.x = x;
        this.y = y;
    }

    @Override
    public int compareTo(Game ob)
    {
        if(this.x < ob.x)
            return -1;
        else if(this.x > ob.x)
            return 1;
        else
        {
            if(this.y < ob.y)
                return -1;
            else if(this.y > ob.y)
                return 1;
            else
                return 0;
        }
    }
}
class MergeSortInt
{
    // Merges two subarrays of arr[].
    // First subarray is arr[l..m]
    // Second subarray is arr[m+1..r]
    void merge(int arr[], int l, int m, int r) {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        int L[] = new int[n1];
        int R[] = new int[n2];

        /*Copy data to temp arrays*/
        for (int i = 0; i < n1; ++i)
            L[i] = arr[l + i];
        for (int j = 0; j < n2; ++j)
            R[j] = arr[m + 1 + j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2) {
            if (L[i] <= R[j]) {
                arr[k] = L[i];
                i++;
            } else {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1) {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2) {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    void sort(int arr[], int l, int r) {
        if (l < r) {
            // Find the middle point
            int m = (l + r) / 2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr, m + 1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }

}
class MergeSortLong
{
    // Merges two subarrays of arr[].
    // First subarray is arr[l..m]
    // Second subarray is arr[m+1..r]
    void merge(long arr[], int l, int m, int r) {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        long L[] = new long[n1];
        long R[] = new long[n2];

        /*Copy data to temp arrays*/
        for (int i = 0; i < n1; ++i)
            L[i] = arr[l + i];
        for (int j = 0; j < n2; ++j)
            R[j] = arr[m + 1 + j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2) {
            if (L[i] <= R[j]) {
                arr[k] = L[i];
                i++;
            } else {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1) {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2) {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    void sort(long arr[], int l, int r) {
        if (l < r) {
            // Find the middle point
            int m = (l + r) / 2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr, m + 1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }
}
class Node
{
    String a;
    String b;
    Node(String s1,String s2)
    {
        this.a = s1;
        this.b = s2;
    }
    @Override
    public boolean equals(Object ob)
    {
        if(ob == null)
            return false;
        if(!(ob instanceof Node))
            return false;
        if(ob == this)
            return true;
        Node obj = (Node)ob;
        if(this.a.equals(obj.a) && this.b.equals(obj.b))
            return true;
        return false;
    }

    @Override
    public int hashCode()
    {
        return (int)this.a.length();
    }
}
class Reader
{
    final private int BUFFER_SIZE = 1 << 16;
    private DataInputStream din;
    private byte[] buffer;
    private int bufferPointer, bytesRead;

    public Reader()
    {
        din = new DataInputStream(System.in);
        buffer = new byte[BUFFER_SIZE];
        bufferPointer = bytesRead = 0;
    }

    public Reader(String file_name) throws IOException
    {
        din = new DataInputStream(new FileInputStream(file_name));
        buffer = new byte[BUFFER_SIZE];
        bufferPointer = bytesRead = 0;
    }

    public String readLine() throws IOException
    {
        byte[] buf = new byte[64]; // line length
        int cnt = 0, c;
        while ((c = read()) != -1)
        {
            if (c == '\n')
                break;
            buf[cnt++] = (byte) c;
        }
        return new String(buf, 0, cnt);
    }

    public int nextInt() throws IOException
    {
        int ret = 0;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();
        do
        {
            ret = ret * 10 + c - '0';
        }  while ((c = read()) >= '0' && c <= '9');

        if (neg)
            return -ret;
        return ret;
    }

    public long nextLong() throws IOException
    {
        long ret = 0;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();
        do {
            ret = ret * 10 + c - '0';
        }
        while ((c = read()) >= '0' && c <= '9');
        if (neg)
            return -ret;
        return ret;
    }

    public double nextDouble() throws IOException
    {
        double ret = 0, div = 1;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();

        do {
            ret = ret * 10 + c - '0';
        }
        while ((c = read()) >= '0' && c <= '9');

        if (c == '.')
        {
            while ((c = read()) >= '0' && c <= '9')
            {
                ret += (c - '0') / (div *= 10);
            }
        }

        if (neg)
            return -ret;
        return ret;
    }

    private void fillBuffer() throws IOException
    {
        bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
        if (bytesRead == -1)
            buffer[0] = -1;
    }

    private byte read() throws IOException
    {
        if (bufferPointer == bytesRead)
            fillBuffer();
        return buffer[bufferPointer++];
    }

    public void close() throws IOException
    {
        if (din == null)
            return;
        din.close();
    }
}
class FenwickTree
{
    public void update(long[] fenwickTree,long delta,int index)
    {
        index += 1;
        while(index < fenwickTree.length)
        {
            fenwickTree[index] += delta;
            index = index + (index & (-index));
        }
    }
    public long prefixSum(long[] fenwickTree,int index)
    {
        long sum = 0L;
        index += 1;
        while(index > 0)
        {
            sum += fenwickTree[index];
            index -= (index & (-index));
        }
        return sum;
    }
}
class SegmentTree
{
    public int nextPowerOfTwo(int num)
    {
        if(num == 0)
            return 1;
        if(num > 0 && (num & (num - 1)) == 0)
            return num;
        while((num &(num - 1)) > 0)
        {
            num = num & (num - 1);
        }
        return num << 1;
    }
    public int[] createSegmentTree(int[] input)
    {
        int np2 = nextPowerOfTwo(input.length);
        int[] segmentTree = new int[np2 * 2 - 1];

        for(int i=0;i<segmentTree.length;i++)
            segmentTree[i] = Integer.MIN_VALUE;

        constructSegmentTree(segmentTree,input,0,input.length-1,0);
        return segmentTree;

    }
    private void constructSegmentTree(int[] segmentTree,int[] input,int low,int high,int pos)
    {
        if(low == high)
        {
            segmentTree[pos] = input[low];
            return;
        }
        int mid = (low + high)/ 2;
        constructSegmentTree(segmentTree,input,low,mid,2*pos + 1);
        constructSegmentTree(segmentTree,input,mid+1,high,2*pos + 2);
        segmentTree[pos] = Math.max(segmentTree[2*pos + 1],segmentTree[2*pos + 2]);
    }
    public int rangeMinimumQuery(int []segmentTree,int qlow,int qhigh,int len)
    {
        return rangeMinimumQuery(segmentTree,0,len-1,qlow,qhigh,0);
    }
    private int rangeMinimumQuery(int segmentTree[],int low,int high,int qlow,int qhigh,int pos)
    {
        if(qlow <= low && qhigh >= high){
            return segmentTree[pos];
        }
        if(qlow > high || qhigh < low){
            return Integer.MIN_VALUE;
        }
        int mid = (low+high)/2;
        return Math.max(rangeMinimumQuery(segmentTree, low, mid, qlow, qhigh, 2 * pos + 1),
                rangeMinimumQuery(segmentTree, mid + 1, high, qlow, qhigh, 2 * pos + 2));
    }
}