#include <bits/stdc++.h>
using namespace std;
long long GCDFast(long long a, long long b) {
  while (b) b ^= a ^= b ^= a %= b;
  return a;
}
int dx[8] = {-1, 0, 1, 0, -1, 1, 1, -1};
int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
vector<int> G[100010];
int init[100010], goal[100010];
int visit[100010];
vector<int> res;
void dfs(int src, int level, int odd, int even) {
  visit[src] = 1;
  if ((level % 2 == 0 && even) || (level % 2 == 1 && odd))
    init[src] = (init[src] + 1) % 2;
  if (init[src] != goal[src]) {
    res.push_back(src);
    if (level % 2 == 0)
      even = (even + 1) % 2;
    else
      odd = (odd + 1) % 2;
  }
  for (int i = 0; i < G[src].size(); i++) {
    int x = G[src][i];
    if (!visit[x]) {
      dfs(x, level + 1, odd, even);
    }
  }
}
int main() {
  int n, i, j, k, temp, m;
  int x, u, v, y, z, sum, test_case = 0, length, ans, test = 0, l, w, num, q;
  int input, testCase = 0;
  ios::sync_with_stdio(false);
  while (cin >> n) {
    for (i = 0; i < n - 1; i++) {
      cin >> x >> y;
      G[x].push_back(y);
      G[y].push_back(x);
    }
    for (i = 1; i <= n; i++) cin >> init[i];
    for (i = 1; i <= n; i++) cin >> goal[i];
    res.clear();
    memset(visit, 0, sizeof visit);
    for (i = 1; i <= n; i++) {
      if (!visit[i]) dfs(i, 1, 0, 0);
    }
    cout << res.size() << "\n";
    for (i = 0; i < res.size(); i++) cout << res[i] << "\n";
  }
  return 0;
}
