#include <bits/stdc++.h>
using namespace std;
vector<int> V[111111];
int a[111111], b[111111], n;
vector<int> ans;
int o[111111], e[111111];
int vis[111111];
void dfs(int x, int dep) {
  vis[x] = 1;
  for (int i = 0; i < V[x].size(); i++) {
    int t = V[x][i];
    if (vis[t]) continue;
    o[t] = o[x], e[t] = e[x];
    if ((dep + 1) % 2 == 1) {
      if (o[x]) {
        a[t] = (a[t] + 1) % 2;
      }
      if (a[t] != b[t]) {
        a[t] = b[t];
        o[t] = (o[t] + 1) % 2;
        ans.push_back(t);
      }
    } else {
      if (e[x]) {
        a[t] = (a[t] + 1) % 2;
      }
      if (a[t] != b[t]) {
        a[t] = b[t];
        e[t] = (e[t] + 1) % 2;
        ans.push_back(t);
      }
    }
    dfs(t, dep + 1);
  }
}
int main() {
  cin >> n;
  for (int i = 1; i < n; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    V[u].push_back(v);
    V[v].push_back(u);
  }
  for (int i = 1; i <= n; i++) {
    scanf("%d", a + i);
  }
  for (int i = 1; i <= n; i++) {
    scanf("%d", b + i);
  }
  V[0].push_back(1);
  dfs(0, 0);
  cout << ans.size() << endl;
  if (ans.size() == 0)
    ;
  else {
    for (int i = 0; i < ans.size(); i++) printf("%d\n", ans[i]);
  }
  return 0;
}
