#include <bits/stdc++.h>
using namespace std;
vector<long long> g[100001];
long long init[100001], goal[100001];
long long cnt = 0;
bool vis[100001];
vector<long long> vaa;
void fun(long long src, long long odd, long long even, long long level) {
  vis[src] = true;
  if (init[src] == goal[src]) {
    if (level % 2 == 0) {
      if (even % 2 == 1) {
        cnt++;
        even++;
        vaa.push_back(src);
      }
    } else {
      if (odd % 2 == 1) {
        cnt++;
        odd++;
        vaa.push_back(src);
      }
    }
  } else {
    if (level % 2 == 0) {
      if (even % 2 == 0) {
        cnt++;
        even++;
        vaa.push_back(src);
      }
    } else {
      if (odd % 2 == 0) {
        cnt++;
        odd++;
        vaa.push_back(src);
      }
    }
  }
  for (long long i = 0; i < g[src].size(); i++) {
    long long node = g[src][i];
    if (!vis[node]) {
      fun(node, odd, even, level + 1);
    }
  }
}
int main() {
  long long n, i, u, v;
  cin >> n;
  for (i = 1; i <= n - 1; i++) {
    cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  for (i = 1; i <= n; i++) cin >> init[i];
  for (i = 1; i <= n; i++) cin >> goal[i];
  fun(1, 0, 0, 0);
  cout << cnt << endl;
  for (i = 0; i < vaa.size(); i++) cout << vaa[i] << endl;
  return 0;
}
