#include <bits/stdc++.h>
using namespace std;
vector<vector<int> > g;
vector<int> init, goal;
vector<int> ans;
void dfs(int v, int p, bool chet, bool nchet, int dep) {
  if ((dep % 2 == 0 && chet) || (dep % 2 == 1 && nchet)) {
    init[v] = 1 - init[v];
  }
  bool n_chet = chet;
  bool n_nchet = nchet;
  if (init[v] != goal[v]) {
    ans.push_back(v + 1);
    if (dep % 2 == 0) {
      n_chet = !chet;
    } else {
      n_nchet = !nchet;
    }
  }
  for (int i = 0; i < (int)g[v].size(); ++i) {
    int u = g[v][i];
    if (u != p) {
      dfs(u, v, n_chet, n_nchet, dep + 1);
    }
  }
}
int main() {
  int n;
  cin >> n;
  g.resize(n);
  init.resize(n);
  goal.resize(n);
  for (int i = 0; i < n - 1; ++i) {
    int a, b;
    cin >> a >> b;
    g[a - 1].push_back(b - 1);
    g[b - 1].push_back(a - 1);
  }
  for (int i = 0; i < n; ++i) {
    cin >> init[i];
  }
  for (int i = 0; i < n; ++i) {
    cin >> goal[i];
  }
  dfs(0, -1, false, false, 0);
  cout << ans.size() << endl;
  for (int i = 0; i < (int)ans.size(); ++i) {
    cout << ans[i] << endl;
  }
  return 0;
}
