#include <bits/stdc++.h>
using namespace std;
long long mod = 1000000007;
vector<long long> vis(100005);
vector<long long> init(100005);
vector<long long> fin(100005);
vector<long long> res;
struct we {
  long long node, level, even, odd;
};
void bfs(long long root, vector<vector<long long> > &v) {
  vis[root] = 1;
  queue<we> q;
  q.push({root, 0, 0, 0});
  while (!q.empty()) {
    we x = q.front();
    q.pop();
    long long node = x.node;
    long long level = x.level;
    long long even = x.even;
    long long odd = x.odd;
    long long k = init[node];
    if (level & 1) {
      k += odd;
    } else {
      k += even;
    }
    k %= 2;
    if (k != fin[node]) {
      res.push_back(node);
      if (level & 1) {
        odd++;
      } else {
        even++;
      }
    }
    for (long long i = 0; i < v[node].size(); i++) {
      if (vis[v[node][i]] == 0) {
        vis[v[node][i]] = 1;
        q.push({v[node][i], level + 1, even, odd});
      }
    }
  }
}
int32_t main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  long long n;
  cin >> n;
  vector<vector<long long> > v(n + 1);
  for (long long i = 0; i < n - 1; i++) {
    long long a, b;
    cin >> a >> b;
    v[a].push_back(b);
    v[b].push_back(a);
  }
  for (long long i = 1; i <= n; i++) {
    cin >> init[i];
  }
  for (long long i = 1; i <= n; i++) {
    cin >> fin[i];
  }
  bfs(1, v);
  cout << res.size() << "\n";
  for (long long i = 0; i < res.size(); i++) {
    cout << res[i] << "\n";
  }
}
