#include <bits/stdc++.h>
using namespace std;
template <typename T>
T in() {
  char ch;
  T n = 0;
  bool ng = false;
  while (1) {
    ch = getchar();
    if (ch == '-') {
      ng = true;
      ch = getchar();
      break;
    }
    if (ch >= '0' && ch <= '9') break;
  }
  while (1) {
    n = n * 10 + (ch - '0');
    ch = getchar();
    if (ch < '0' || ch > '9') break;
  }
  return (ng ? -n : n);
}
template <typename T>
inline T POW(T B, T P) {
  if (P == 0) return 1;
  if (P & 1)
    return B * POW(B, P - 1);
  else
    return (POW(B, P / 2) * POW(B, P / 2));
}
template <typename T>
inline T Gcd(T a, T b) {
  if (a < 0) return Gcd(-a, b);
  if (b < 0) return Gcd(a, -b);
  return (b == 0) ? a : Gcd(b, a % b);
}
template <typename T>
inline T Lcm(T a, T b) {
  if (a < 0) return Lcm(-a, b);
  if (b < 0) return Lcm(a, -b);
  return a * (b / Gcd(a, b));
}
long long Bigmod(long long base, long long power, long long MOD) {
  long long ret = 1;
  while (power) {
    if (power & 1) ret = (ret * base) % MOD;
    base = (base * base) % MOD;
    power >>= 1;
  }
  return ret;
}
bool isVowel(char ch) {
  ch = toupper(ch);
  if (ch == 'A' || ch == 'U' || ch == 'I' || ch == 'O' || ch == 'E')
    return true;
  return false;
}
template <typename T>
long long isLeft(T a, T b, T c) {
  return (a.x - b.x) * (b.y - c.y) - (b.x - c.x) * (a.y - b.y);
}
long long ModInverse(long long number, long long MOD) {
  return Bigmod(number, MOD - 2, MOD);
}
bool isConst(char ch) {
  if (isalpha(ch) && !isVowel(ch)) return true;
  return false;
}
int toInt(string s) {
  int sm;
  stringstream ss(s);
  ss >> sm;
  return sm;
}
bool isPrime(long long val) {
  if (val == 2) return true;
  if (val % 2 == 0 || val == 1) return false;
  long long sqrt_N = (long long)((double)sqrt(val));
  for (long long i = 3; i <= sqrt_N; i += 2) {
    if (val % i == 0) return false;
  }
  return true;
}
template <class T>
string convert(T _input) {
  stringstream blah;
  blah << _input;
  return blah.str();
}
map<string, long long> month;
void Month() {
  month["January"] = 1, month["February"] = 2, month["March"] = 3,
  month["April"] = 4, month["May"] = 5, month["June"] = 6;
  month["July"] = 7, month["August"] = 8, month["September"] = 9,
  month["October"] = 10, month["November"] = 11, month["December"] = 12;
}
long long n, m;
long long a[100005];
long long b[100005];
long long level[100005];
bool ck[100005];
vector<long long> V[100005], res;
void DFS(long long u, long long jor, long long bjor) {
  long long d, i;
  d = V[u].size();
  ck[u] = 1;
  if (level[u] % 2) {
    long long state = bjor % 2;
    if (state) {
      if (a[u] == b[u]) {
        bjor++;
        res.push_back(u);
      }
    } else {
      if (a[u] != b[u]) {
        bjor++;
        res.push_back(u);
      }
    }
  } else {
    long long state = jor % 2;
    if (state) {
      if (a[u] == b[u]) {
        jor++;
        res.push_back(u);
      }
    } else {
      if (a[u] != b[u]) {
        jor++;
        res.push_back(u);
      }
    }
  }
  for (i = 0; i <= d - 1; i++) {
    long long v = V[u][i];
    if (ck[v] == 0) {
      level[v] = level[u] + 1;
      DFS(v, jor, bjor);
    }
  }
}
int main() {
  long long i, j, k, t, j1;
  n = in<long long>();
  for (i = 1; i <= n - 1; i++) {
    long long u, v;
    u = in<long long>(), v = in<long long>();
    V[u].push_back(v);
    V[v].push_back(u);
  }
  for (i = 1; i <= n; i++) {
    a[i] = in<long long>();
  }
  for (i = 1; i <= n; i++) {
    b[i] = in<long long>();
  }
  level[1] = 1;
  DFS(1, 0, 0);
  long long tot = res.size();
  printf("%lld\n", tot);
  for (i = 0; i <= tot - 1; i++) {
    printf("%lld\n", res[i]);
  }
  return 0;
}
