#include <bits/stdc++.h>
using namespace std;
list<int> graf[100100];
int init[100100];
int goal[100100];
void rec(int x, int anc, int flip_mask, int depth_parity,
         vector<int>& reconstruction) {
  init[x] ^= ((flip_mask >> depth_parity) & 1);
  if (init[x] != goal[x]) {
    flip_mask ^= (1 << depth_parity);
    init[x] ^= 1;
    reconstruction.push_back(x);
  }
  for (list<int>::iterator it = graf[x].begin(); it != graf[x].end(); ++it) {
    if (*it == anc) {
      continue;
    }
    rec(*it, x, flip_mask, 1 - depth_parity, reconstruction);
  }
}
int main(void) {
  int n;
  scanf("%d", &n);
  for (int i = 1; i < n; ++i) {
    int a, b;
    scanf("%d%d", &a, &b);
    --a;
    --b;
    graf[a].push_back(b);
    graf[b].push_back(a);
  }
  for (int i = 0; i < n; ++i) scanf("%d", init + i);
  for (int i = 0; i < n; ++i) scanf("%d", goal + i);
  vector<int> recon;
  rec(0, -1, 0, 0, recon);
  printf("%d\n", (int)recon.size());
  for (int i = 0; i < recon.size(); ++i) {
    printf("%d\n", recon[i] + 1);
  }
  return 0;
}
