#include <bits/stdc++.h>
using namespace std;
const int N = 100 * 1000 + 100;
int n, it[N], g[N], mark[N], p[N];
pair<int, int> d[N];
vector<int> adj[N], op;
void dfs(int v, int par) {
  p[v] = par;
  for (auto u : adj[v])
    if (u != par)
      p[u] = v, d[u].first = d[v].first + 1, d[u].second = u, dfs(u, v);
}
int main() {
  cin >> n;
  for (int i = 0, x, y; i < n - 1; i++) {
    cin >> x >> y;
    x--, y--;
    adj[x].push_back(y);
    adj[y].push_back(x);
  }
  for (int i = 0; i < n; i++) cin >> it[i];
  for (int i = 0; i < n; i++) cin >> g[i];
  mark[-1] = 0;
  dfs(0, -1);
  sort(d, d + n);
  for (int k = 0; k < n; k++) {
    int i = d[k].second;
    mark[i] = mark[p[p[i]]];
    if (it[i] != g[i] && mark[i] % 2 == 0) op.push_back(i), mark[i]++;
    if (it[i] == g[i] && mark[i] % 2 != 0) op.push_back(i), mark[i]++;
  }
  cout << op.size() << endl;
  for (int i = 0; i < (int)op.size(); i++) cout << op[i] + 1 << endl;
  return 0;
}
