#include <bits/stdc++.h>
using namespace std;
const int SIZE = 100005;
vector<bool> visit(SIZE, 0);
vector<int> e[SIZE];
vector<int> x(SIZE, 0), goal(SIZE, 0), ans;
void DFS(int s, int o, int ev, int level) {
  visit[s] = true;
  for (auto i : e[s]) {
    if (!visit[i]) {
      if (level % 2 == 1) {
        if (o & 1) x[i] = (x[i] + 1) % 2;
        if (x[i] == goal[i])
          DFS(i, o, ev, level + 1);
        else
          ans.push_back(i), DFS(i, o + 1, ev, level + 1);
      } else {
        if (ev & 1) x[i] = (x[i] + 1) % 2;
        if (x[i] == goal[i])
          DFS(i, o, ev, level + 1);
        else
          ans.push_back(i), DFS(i, o, ev + 1, level + 1);
      }
    }
  }
}
void solve() {
  int n;
  cin >> n;
  for (int i = 0; i < n - 1; i++) {
    int a, b;
    cin >> a >> b;
    e[a].push_back(b);
    e[b].push_back(a);
  }
  for (int i = 1; i <= n; i++) cin >> x[i];
  for (int i = 1; i <= n; i++) cin >> goal[i];
  if (x[1] == goal[1])
    DFS(1, 0, 0, 1);
  else
    ans.push_back(1), DFS(1, 0, 1, 1);
  cout << ans.size() << endl;
  for (auto i : ans) {
    cout << i << endl;
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cerr << fixed << setprecision(15);
  solve();
  return 0;
}
