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 *init*<sub class="lower-index">*i*</sub>, 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 *goal*<sub class="lower-index">*i*</sub>, which can also be only 0 or 1. You need to reach the goal of the game by using minimum number of operations.
The first line contains an integer *n* (1 ≤ *n* ≤ 10<sup class="upper-index">5</sup>). Each of the next *n* - 1 lines contains two integers *u*<sub class="lower-index">*i*</sub> and *v*<sub class="lower-index">*i*</sub> (1 ≤ *u*<sub class="lower-index">*i*</sub>, *v*<sub class="lower-index">*i*</sub> ≤ *n*; *u*<sub class="lower-index">*i*</sub> ≠ *v*<sub class="lower-index">*i*</sub>) meaning there is an edge between nodes *u*<sub class="lower-index">*i*</sub> and *v*<sub class="lower-index">*i*</sub>. 

The next line contains *n* integer numbers, the *i*-th of them corresponds to *init*<sub class="lower-index">*i*</sub> (*init*<sub class="lower-index">*i*</sub> is either 0 or 1). The following line also contains *n* integer numbers, the *i*-th number corresponds to *goal*<sub class="lower-index">*i*</sub> (*goal*<sub class="lower-index">*i*</sub> is either 0 or 1).
import sys
import math
from collections import defaultdict

MAXNUM = math.inf
MINNUM = -1 * math.inf
ASCIILOWER = 97
ASCIIUPPER = 65


def getInt():
    return int(sys.stdin.readline().rstrip())


def getInts():
    return map(int, sys.stdin.readline().rstrip().split(" "))


def getString():
    return sys.stdin.readline().rstrip()


def printOutput(ans):
    sys.stdout.write()
    pass


class dfsData:
    def __init__(self):
        self.total = 0


def dfsHelper(adjList, start, goal, cur, explored, xor, data):
    if start[cur] != goal[cur]:
        data.total += 1
        xor = (xor + 1) % 2

    for ele in adjList[cur]:
        if ele not in explored:
            explored[ele] = True
            dfs(adjList, start, goal, ele, explored, xor, data)


def dfs(adjList, start, goal):
    explored = dict()
    explored[1] = True  # root
    data = dfsData()
    dfsHelper(adjList, start, goal, 1, explored, 0, data)
    return data.total


def iterdfs(adjList, init, goal):
    stack = []
    start = (1, 0)  # node, xorstate
    stack.append(start)
    explored = {}
    explored[start] = True
    total = 0
    flip = []
    while stack:
        curNode, xor = stack.pop()
        if (init[curNode] + xor) % 2 != goal[curNode]:
            total += 1
            xor = (xor + 1) % 2
            flip.append(curNode)

        for ele in adjList[curNode]:
            if ele not in explored:
                explored[ele] = True
                stack.append((ele, xor))

    return total, flip


def solve(adjList, start, goal):
    """working assumption: it's always better to go down the tree"""
    return iterdfs(adjList, start, goal)


def readinput():
    edges = getInt()
    adjList = defaultdict(list)
    for _ in range(edges - 1):
        a, b = getInts()
        adjList[a].append(b)
        adjList[b].append(a)
    start = [0] + list(getInts())
    goal = [0] + list(getInts())
    t, f = solve(adjList, start, goal)
    print(t)
    for ele in f:
        print(ele)


readinput()
