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.*;
import java.math.*;

public class Practice

{ 
	 static FastReader sc=new FastReader(); 
	 static int mod=(int)Math.pow(10, 9)+7;
	 static int dp[][];
	 static ArrayList<Integer> l=new ArrayList<Integer>();
	 
		  public static void main(String[] args) 
    {
			   PrintWriter out=new PrintWriter(System.out);
			  //StringBuffer sb=new StringBuffer("");
			  
			  int ttt=1;
			     //ttt =i(); 
		        outer :while (ttt-- > 0) 
				{
			        int n=i()+1;
		        	int m=n-2;
		        	ArrayList<Integer> A[]=new ArrayList[n];
		        	for(int i=0;i<A.length;i++) {
		        		A[i]=new ArrayList<Integer>();
		        	}
		        	int d[]=new int[n];
		        	for(int i=0;i<m;i++) {
		        		int a=i();
		        		int b=i();
		        		A[a].add(b);
		        		A[b].add(a);
		        		d[a]++;
		        		d[b]++;
		        		
		        	}
		        	int B[]=input(n-1);
		        	int C[]=input(n-1);
		        	boolean v[]=new boolean[n];
		        	dfs(A, 1, v, d, 0);
		        	Arrays.fill(v, false);
		        	dfs(A, 1, v, B, C,d,0,0);
		        	out.println(l.size());
		        	for(int i : l)
		        		out.println(i+" ");
		        	
		        	
		        	
		        	
				}
			     out.close();
		    	//System.out.println(sb.toString());
		        	
    }
		  private static void dfs(ArrayList<Integer> [] A, int s, boolean[] v,int B[],int C[],int level[],int even,int odd) {
				v[s]=true;
				if(level[s]%2==0) {
					if(even==1) {
						B[s-1]^=1;
						if(B[s-1]!=C[s-1]) {
							B[s-1]=C[s-1];
							even=0;
							l.add(s);
						}
					}
					else {
						if(B[s-1]!=C[s-1]) {
							B[s-1]=C[s-1];
							even=1;
							l.add(s);
						}
					}
				}
				else {
					if(odd==1) {
						B[s-1]^=1;
						if(B[s-1]!=C[s-1]) {
							B[s-1]=C[s-1];
							odd=0;
							
							l.add(s);
							
						}
					}
					else {
						if(B[s-1]!=C[s-1]) {
							B[s-1]=C[s-1];
							odd=1;
							l.add(s);
						}
					}
				}
				for(int i=0;i<A[s].size();i++) {
					int child=A[s].get(i);
					if(!v[child]) {
						dfs(A, child, v,B,C,level,even,odd);
					}
				}
				
			}
		  private static void dfs(ArrayList<Integer> [] A, int s, boolean[] v,int dis[],int d) {
				v[s]=true;
				dis[s]=d;
				for(int i=0;i<A[s].size();i++) {
					int child=A[s].get(i);
					if(!v[child]) {
						dfs(A, child, v,dis,d+1);
					}
				}
				
			}






static int[] input(int n) {
	int A[]=new int[n];
	   for(int i=0;i<n;i++) {
		   A[i]=sc.nextInt();
	   }
	   return A;
   }
static long[] inputL(int n) {
	long A[]=new long[n];
	   for(int i=0;i<n;i++) {
		   A[i]=sc.nextLong();
	   }
	   return A;
   }
static String[] inputS(int n) {
	String A[]=new String[n];
	   for(int i=0;i<n;i++) {
		   A[i]=sc.next();
	   }
	   return A;
   }
static long sum(int A[]) {
	long sum=0;
	for(int i : A) {
		sum+=i;
	}
	return sum;
}

static void input(int A[],int B[]) {
	   for(int i=0;i<A.length;i++) {
		   A[i]=sc.nextInt();
		   B[i]=sc.nextInt();
	   }
}
static int[][] input(int n,int m){
	int A[][]=new int[n][m];
	for(int i=0;i<n;i++) {
		for(int j=0;j<m;j++) {
			A[i][j]=i();
		}
	}
	return A;
}
static int max(int A[]) {
	int max=Integer.MIN_VALUE;
	for(int i=0;i<A.length;i++) {
		max=Math.max(max, A[i]);
	}
	return max;
}
static int min(int A[]) {
	int min=Integer.MAX_VALUE;
	for(int i=0;i<A.length;i++) {
		min=Math.min(min, A[i]);
	}
	return min;
}
static long max(long A[]) {
	long max=Long.MIN_VALUE;
	for(int i=0;i<A.length;i++) {
		max=Math.max(max, A[i]);
	}
	return max;
}
static long min(long A[]) {
	long min=Long.MAX_VALUE;
	for(int i=0;i<A.length;i++) {
		min=Math.min(min, A[i]);
	}
	return min;
}
static long mod(long x) {
	 int mod=1000000007;
	  return ((x%mod + mod)%mod);
}

     static int i() {
    	 return sc.nextInt();
     }
     static String s() {
    	 return sc.next();
     }
     static long l() {
    	 return sc.nextLong();
     }  
     static void sort(int[] A){
        int n = A.length;
        Random rnd = new Random();
        for(int i=0; i<n; ++i){
            int tmp = A[i];
            int randomPos = i + rnd.nextInt(n-i);
            A[i] = A[randomPos];
            A[randomPos] = tmp;
        }
        Arrays.sort(A);
     }
     static void sort(long[] A){
	        int n = A.length;
	        Random rnd = new Random();
	        for(int i=0; i<n; ++i){
	            long tmp = A[i];
	            int randomPos = i + rnd.nextInt(n-i);
	            A[i] = A[randomPos];
	            A[randomPos] = tmp;
	        }
	        Arrays.sort(A);
	     }
     static HashMap<Integer,Integer> hash(int A[]){
   	  HashMap<Integer,Integer> map=new HashMap<Integer, Integer>();
   	  for(int i : A) {
   		  if(map.containsKey(i)) {
   			  map.put(i, map.get(i)+1);
   		  }
   		  else {
   			  map.put(i, 1);
   		  }
   	  }
   	  return map;
     }
  static String sort(String s) {
 	 Character ch[]=new Character[s.length()];
 	 for(int i=0;i<s.length();i++) {
 		 ch[i]=s.charAt(i);
 	 }
 	 Arrays.sort(ch);
 	 StringBuffer st=new StringBuffer("");
 	 for(int i=0;i<s.length();i++) {
 		 st.append(ch[i]);
 	 }
 	 return st.toString();
  }
     static boolean prime(int n) 
	    { 
	        if (n <= 1) 
	            return false; 
	        if (n <= 3) 
	            return true; 
	        if (n % 2 == 0 || n % 3 == 0) 
	            return false; 
	        double sq=Math.sqrt(n);
	  
	        for (int i = 5; i <= sq; i = i + 6) 
	            if (n % i == 0 || n % (i + 2) == 0) 
	                return false; 
	        return true; 
	    } 
     static boolean prime(long n) 
	    { 
	        if (n <= 1) 
	            return false; 
	        if (n <= 3) 
	            return true; 
	        if (n % 2 == 0 || n % 3 == 0) 
	            return false; 
	        double sq=Math.sqrt(n);
	  
	        for (int i = 5; i <= sq; i = i + 6) 
	            if (n % i == 0 || n % (i + 2) == 0) 
	                return false; 
	        return true; 
	    } 
     static int gcd(int a, int b) 
     { 
         if (a == 0) 
             return b; 
         return gcd(b % a, a); 
     } 
     static long gcd(long a, long b) 
     { 
         if (a == 0) 
             return b; 
         return gcd(b % a, a); 
     } 
     static class Pair implements Comparable<Pair>
     {
    	 int x;
    	 int y;
    	 Pair(int x,int y){
    		 this.x=x;
    		 this.y=y;
    	 }
		@Override
		public int compareTo(Pair o) {
			if(this.x>o.x)
				return -1;
			else if(this.x<o.x)
				return 1;
			else
				return this.y-o.y;
		}
     }
        
    static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } 
}