#include <bits/stdc++.h>
using namespace std;
template <class T>
T sqr(T x) {
  return x * x;
}
template <class T>
T gcd(T a, T b) {
  return (b != 0 ? gcd<T>(b, a % b) : a);
}
template <class T>
T lcm(T a, T b) {
  return (a / gcd<T>(a, b) * b);
}
template <class T>
inline T bigmod(T p, T e, T M) {
  if (e == 0) return 1;
  if (e % 2 == 0) {
    long long int t = bigmod(p, e / 2, M);
    return (T)((t * t) % M);
  }
  return (T)((long long int)bigmod(p, e - 1, M) * (long long int)p) % M;
}
template <class T>
inline T bigexp(T p, T e) {
  if (e == 0) return 1;
  if (e % 2 == 0) {
    long long int t = bigexp(p, e / 2);
    return (T)((t * t));
  }
  return (T)((long long int)bigexp(p, e - 1) * (long long int)p);
}
template <class T>
inline T modinverse(T a, T M) {
  return bigmod(a, M - 2, M);
}
int dx4[] = {1, 0, -1, 0};
int dy4[] = {0, 1, 0, -1};
int dx8[] = {1, 1, 0, -1, -1, -1, 0, 1};
int dy8[] = {0, 1, 1, 1, 0, -1, -1, -1};
int month[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int n, u, v, mn, mx;
vector<int> edges[100005];
int a[100005], b[100005], cnt, c[100005];
bool taken[100005];
void dfs(int node, int od, int ev, int level) {
  if (taken[node] == true) return;
  taken[node] = true;
  if (level % 2 == 0) {
    a[node] = (a[node] + ev) % 2;
    if (a[node] != b[node]) {
      cnt++;
      ev++;
      c[cnt] = node;
    }
  } else {
    a[node] = (a[node] + od) % 2;
    if (a[node] != b[node]) {
      cnt++;
      od++;
      c[cnt] = node;
    }
  }
  for (int i = 0; i < edges[node].size(); i++) {
    int v = edges[node][i];
    dfs(v, od, ev, level + 1);
  }
  return;
}
int main() {
  scanf("%d", &n);
  for (__typeof(n - 1) i = (1); i <= (n - 1); i++) {
    scanf("%d %d", &u, &v);
    edges[u].push_back(v);
    edges[v].push_back(u);
  }
  for (__typeof(n) i = (1); i <= (n); i++) scanf("%d", &a[i]);
  for (__typeof(n) i = (1); i <= (n); i++) scanf("%d", &b[i]);
  dfs(1, 0, 0, 0);
  printf("%d\n", cnt);
  for (__typeof(cnt) i = (1); i <= (cnt); i++) printf("%d\n", c[i]);
  return 0;
}
