#include <bits/stdc++.h>
using namespace std;
vector<long long int> edge[100005];
vector<long long int> curr(100005);
vector<long long int> goal(100005);
vector<long long int> flip(100005);
vector<long long int> par(100005);
vector<long long int> order;
long long int cnt;
void dfs(long long int u) {
  if (flip[par[par[u]]] != 0) {
    flip[u] = flip[par[par[u]]];
  }
  if (goal[u] != ((curr[u] + (flip[u] & 1)) % 2)) {
    cnt++;
    flip[u]++;
    order.push_back(u);
  }
  for (auto x : edge[u]) {
    if (x != par[u]) {
      par[x] = u;
      dfs(x);
    }
  }
}
void solve() {
  long long int n;
  cin >> n;
  for (long long int i = 0; i < n - 1; i++) {
    long long int a, b;
    cin >> a >> b;
    edge[a].push_back(b);
    edge[b].push_back(a);
  }
  for (long long int i = 1; i <= n; i++) {
    cin >> curr[i];
  }
  for (long long int i = 1; i <= n; i++) {
    cin >> goal[i];
  }
  par[1] = 0;
  cnt = 0;
  dfs(1);
  cout << cnt << '\n';
  for (long long int i = 0; i < order.size(); i++) {
    cout << order[i] << '\n';
  }
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long int T;
  T = 1;
  while (T--) {
    solve();
  }
}
