#include <bits/stdc++.h>
using namespace std;
vector<int> c;
vector<bool> used;
void dfs(int u, vector<vector<int>>& v) {
  used[u] = 1;
  for (int i = 0; i < v[u].size(); i++) {
    if (c[u] == c[v[u][i]] && !used[v[u][i]]) {
      dfs(v[u][i], v);
    }
  }
}
int main() {
  int n;
  cin >> n;
  vector<vector<int>> v(n);
  c.resize(n);
  used.resize(n, 0);
  vector<int> cnt(110000);
  for (int i = 0; i < n - 1; i++) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    v[a].push_back(b);
    v[b].push_back(a);
  }
  for (int i = 0; i < n; i++) {
    cin >> c[i];
  }
  for (int i = 0; i < n; i++) {
    if (!used[i]) {
      cnt[c[i]]++;
      dfs(i, v);
    }
  }
  multiset<int> data;
  for (int i = 0; i < 100010; i++) {
    for (int j = 0; j < cnt[i]; j++) {
      data.insert(i);
    }
  }
  for (int i = 0; i < n; i++) {
    bool check = 0;
    multiset<int> tmp;
    for (int j = 0; j < v[i].size(); j++) {
      if (c[v[i][j]] == c[i]) {
        check = 1;
      }
      tmp.insert(c[v[i][j]]);
    }
    if (!check) {
      tmp.insert(c[i]);
    }
    if (tmp == data) {
      cout << "YES" << endl;
      cout << i + 1 << endl;
      return 0;
    }
  }
  cout << "NO" << endl;
}
