#include <bits/stdc++.h>
using namespace std;
const int MAX = 100010;
vector<int> a[MAX], ans;
int x, y, n;
bool v[MAX], d[MAX], f[MAX], l[MAX], odd[MAX], even[MAX];
void DFS(int start) {
  v[start] = true;
  if (d[start] && odd[start]) {
    f[start] = (1 - f[start]);
  }
  if (!d[start] && even[start]) {
    f[start] = (1 - f[start]);
  }
  if (f[start] != l[start]) {
    ans.push_back(start);
    if (d[start]) {
      odd[start] = (1 - odd[start]);
    } else {
      even[start] = (1 - even[start]);
    }
  }
  int current;
  for (int i = 0; i < a[start].size(); i++) {
    current = a[start][i];
    if (!v[current]) {
      d[current] = (1 - d[start]);
      odd[current] = odd[start];
      even[current] = even[start];
      DFS(current);
    }
  }
}
int main() {
  cin >> n;
  for (int i = 1; i < n; i++) {
    cin >> x >> y;
    a[x].push_back(y);
    a[y].push_back(x);
  }
  for (int i = 1; i <= n; i++) {
    cin >> f[i];
  }
  for (int i = 1; i <= n; i++) {
    cin >> l[i];
  }
  DFS(1);
  cout << ans.size() << "\n";
  for (int i = 0; i < ans.size(); i++) {
    cout << ans[i] << "\n";
  }
  cout << "\n";
  return 0;
}
