#include <bits/stdc++.h>
using namespace std;
queue<int> q;
set<int> d[100100], ans;
vector<int> v[100100];
int dis[100100], z, i, n, x, y, p[100100], co[100100], ce[100100], op,
    goal[100100], now[100100];
void bfs(int x) {
  int ch;
  q.push(x);
  while (!q.empty()) {
    x = q.front();
    q.pop();
    for (int i = 0; i < v[x].size(); i++) {
      ch = v[x][i];
      if (dis[ch] == false) {
        q.push(ch);
        p[ch] = x;
        dis[ch] = dis[x] + 1;
        d[dis[ch]].insert(ch);
      }
    }
  }
}
int main() {
  cin >> n;
  for (i = 0; i < n - 1; i++) {
    cin >> x >> y;
    v[x].push_back(y);
    v[y].push_back(x);
  }
  for (i = 1; i <= n; i++) cin >> now[i];
  for (i = 1; i <= n; i++) cin >> goal[i];
  dis[1] = 1;
  d[1].insert(1);
  bfs(1);
  p[1] = 1;
  if (now[1] != goal[1]) {
    ans.insert(1);
    op++;
    co[1] = 1;
  }
  for (i = 2; i <= n; i++) {
    while (d[i].size()) {
      z = *d[i].begin();
      d[i].erase(z);
      if (dis[z] % 2 == 1) {
        ce[z] = ce[p[z]];
        co[z] = co[p[z]];
        if ((now[z] != goal[z] && co[z] == 0) ||
            (now[z] == goal[z] && co[z] == 1)) {
          ans.insert(z);
          co[z] = 1 - co[z];
          op++;
        }
      } else if (dis[z] % 2 == 0) {
        ce[z] = ce[p[z]];
        co[z] = co[p[z]];
        if ((now[z] != goal[z] && ce[z] == 0) ||
            (now[z] == goal[z] && ce[z] == 1)) {
          ans.insert(z);
          ce[z] = 1 - ce[z];
          op++;
        }
      }
    }
  }
  cout << op << endl;
  set<int>::iterator it;
  for (it = ans.begin(); it != ans.end(); it++) cout << *it << " ";
  return 0;
}
