#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5 + 5;
void pairsort(long long a[], long long b[], long long n) {
  pair<long long, long long> pairt[n];
  for (long long i = 0; i < n; i++) {
    pairt[i].first = a[i];
    pairt[i].second = b[i];
  }
  sort(pairt, pairt + n);
  for (long long i = 0; i < n; i++) {
    a[i] = pairt[i].first;
    b[i] = pairt[i].second;
  }
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long isPrime(long long n) {
  if (n < 2) return 0;
  if (n < 4) return 1;
  if (n % 2 == 0 or n % 3 == 0) return 0;
  for (long long i = 5; i * i <= n; i += 6)
    if (n % i == 0 or n % (i + 2) == 0) return 0;
  return 1;
}
long long C(long long n, long long r) {
  if (r > n - r) r = n - r;
  long long ans = 1;
  for (long long i = 1; i <= r; i++) {
    ans *= n - r + i;
    ans /= i;
  }
  return ans;
}
long long mod = 1e9 + 7;
long long modexpo(long long x, long long p) {
  long long res = 1;
  x = x % mod;
  while (p) {
    if (p % 2) res = res * x;
    p >>= 1;
    x = x * x % mod;
    res %= mod;
  }
  return res;
}
long long n, p, q, a[100005], k1, k2, ff, ss;
vector<long long> v[100005];
set<pair<long long, long long>> s;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  cin >> n;
  for (long long i = 1; i < n; i++) {
    cin >> p >> q;
    v[p].push_back(q), v[q].push_back(p);
  }
  for (long long i = 1; i <= n; i++) cin >> a[i];
  for (long long i = 1; i <= n; i++)
    for (long long j = 0; j < v[i].size(); j++)
      if (a[i] != a[v[i][j]])
        s.insert(make_pair((i < v[i][j] ? i : v[i][j]),
                           (i > v[i][j] ? i : v[i][j])));
  auto it = s.begin();
  pair<long long, long long> pp = *it;
  ff = pp.first, ss = pp.second;
  for (auto it = s.begin(); it != s.end(); it++) {
    pair<long long, long long> pq = *it;
    if (ff != pq.first && ff != pq.second) k1 = 1;
    if (ss != pq.first && ss != pq.second) k2 = 1;
  }
  if (!k1) {
    cout << "YES"
         << "\n"
         << (ff > 1 ? ff : 1);
    return 0;
  }
  if (!k2) {
    cout << "YES"
         << "\n"
         << (ss > 1 ? ss : 1);
    return 0;
  }
  cout << "NO";
  return 0;
}
