#include <bits/stdc++.h>
using namespace std;
const int MAX = 100005;
vector<vector<int> > tree(MAX);
int init[MAX], goal[MAX];
vector<int> ans;
void operations(int i, int even, int odd, int level) {
  if (level % 2 == 0) {
    if ((init[i] + even) % 2 != goal[i]) {
      ++even;
      ans.push_back(i);
    }
  } else {
    if ((init[i] + odd) % 2 != goal[i]) {
      ++odd;
      ans.push_back(i);
    }
  }
  for (int j = 0; j < tree[i].size(); ++j) {
    operations(tree[i][j], even, odd, level + 1);
  }
}
int main() {
  int n;
  cin >> n;
  int a, b;
  vector<bool> pre(MAX, false);
  pre[1] = true;
  for (int i = 0; i < n - 1; ++i) {
    cin >> a >> b;
    if (pre[a]) {
      tree[a].push_back(b);
      pre[b] = true;
    } else {
      tree[b].push_back(a);
      pre[a] = true;
    }
  }
  for (int i = 1; i <= n; ++i) cin >> init[i];
  for (int i = 1; i <= n; ++i) cin >> goal[i];
  operations(1, 0, 0, 1);
  cout << ans.size() << "\n";
  for (int i = 0; i < ans.size(); ++i) cout << ans[i] << "\n";
  return 0;
}
