#include <bits/stdc++.h>
using namespace std;
vector<int> v[100005];
vector<int> ans;
int f[100005];
void dfs(int u, int fa, int a, int b) {
  if (fa ^ f[u]) {
    ans.push_back(u);
    fa ^= 1;
  }
  for (int i = 0; i < v[u].size(); i++) {
    if (v[u][i] != b) dfs(v[u][i], a, fa, u);
  }
}
int main() {
  int n;
  cin >> n;
  for (int i = 1; i < n; i++) {
    int x, y;
    cin >> x >> y;
    v[x].push_back(y);
    v[y].push_back(x);
  }
  for (int i = 1; i <= n; i++) {
    cin >> f[i];
  }
  for (int i = 1; i <= n; i++) {
    int x;
    cin >> x;
    if (x == f[i]) {
      f[i] = 0;
    } else {
      f[i] = 1;
    }
  }
  dfs(1, 0, 0, 0);
  cout << ans.size() << endl;
  for (int i = 0; i < ans.size(); i++) {
    cout << ans[i] << endl;
  }
  return 0;
}
