#include <bits/stdc++.h>
using namespace std;
vector<vector<int> > tree;
vector<int> init, goal, changed;
vector<bool> visited;
int change = 0;
void dfs(int i, int even, int odd, int level) {
  if (visited[i]) return;
  visited[i] = true;
  if (level & 1) {
    if (((init[i - 1] + odd) % 2) != goal[i - 1]) {
      changed.push_back(i);
      change++;
      odd++;
    }
  } else {
    if (((init[i - 1] + even) % 2) != goal[i - 1]) {
      changed.push_back(i);
      change++;
      even++;
    }
  }
  for (int j = 0; j < tree[i].size(); j++) {
    dfs(tree[i][j], even, odd, level + 1);
  }
}
int main() {
  int n, u, v;
  ios::sync_with_stdio(0);
  cin >> n;
  tree.assign(n + 1, vector<int>());
  visited.assign(n + 1, false);
  for (int i = 0; i < n - 1; i++) {
    cin >> u >> v;
    tree[u].push_back(v);
    tree[v].push_back(u);
  }
  for (int i = 0; i < n; i++) {
    cin >> u;
    init.push_back(u);
  }
  while (n--) {
    cin >> u;
    goal.push_back(u);
  }
  dfs(1, 0, 0, 0);
  cout << change << '\n';
  for (int i = 0; i < changed.size(); i++) {
    cout << changed[i] << '\n';
  }
  return 0;
}
