#include <bits/stdc++.h>
using namespace std;
vector<int> ans;
vector<int> bro[100005];
int yo[100005], oy[100005];
int ck[100005];
int n, x, y;
void go(int node, int x, int xx) {
  if (ck[node]) return;
  ck[node] = 1;
  yo[node] = (yo[node] + xx) % 2;
  if (yo[node] != oy[node]) {
    ans.push_back(node);
    xx = (xx + 1) % 2;
  }
  int sz = bro[node].size();
  for (int i = 0; i < sz; i++) {
    go(bro[node][i], xx, x);
  }
}
int main() {
  cin >> n;
  for (int i = 1; i < n; i++) {
    scanf("%d %d", &x, &y);
    bro[x].push_back(y);
    bro[y].push_back(x);
  }
  for (int i = 1; i <= n; i++) {
    scanf("%d", &yo[i]);
  }
  for (int i = 1; i <= n; i++) {
    scanf("%d", &oy[i]);
  }
  go(1, 0, 0);
  n = ans.size();
  cout << n << endl;
  for (int i = 0; i < n; i++) {
    printf("%d\n", ans[i]);
  }
  return 0;
}
