#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
vector<int> g[N], ans;
int goal[N], val[N];
void dfs(int v, int p, int cur) {
  int ncur = cur;
  if (goal[v] != (val[v] + cur) % 2) {
    ncur = 1 - cur;
    ans.push_back(v);
  }
  for (auto u : g[v]) {
    if (u == p) continue;
    for (auto to : g[u]) {
      if (to == v) continue;
      dfs(to, u, ncur);
    }
  }
}
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n - 1; i++) {
    int u, v;
    cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  for (int i = 1; i <= n; i++) cin >> val[i];
  for (int i = 1; i <= n; i++) cin >> goal[i];
  dfs(1, -1, 0);
  for (auto u : g[1]) dfs(u, 1, 0);
  cout << ans.size() << "\n";
  for (auto x : ans) cout << x << "\n";
}
