#include <bits/stdc++.h>   using namespace std;   vector<int> g[100500];   int c[100500];   int n;   bool vis[100500];   bool dfs(int u, int cu) {     if (vis[u]) return 0;     vis[u] = 1;     bool r = 0;     if (c[u] != cu) return 1;     for (int v : g[u]) r |= dfs(v, cu);     return r;   }   int main() {     scanf( %d , &n);     for (int i = 0, qwe = n - 1; i < qwe; ++i) {       int u, v;       scanf( %d%d , &u, &v);       u--;       v--;       g[u].push_back(v);       g[v].push_back(u);     }     for (int i = 0, qwe = n; i < qwe; ++i) scanf( %d , c + i);     int u = -1, sz = 0;     for (int i = 0, qwe = n; i < qwe; ++i) {       set<int> s;       for (int v : g[i])         if (c[i] != c[v]) s.insert(v);       if (s.size() > sz) u = i, sz = s.size();     }     if (u == -1) {       puts( YES n1 );       return 0;     }     vis[u] = 1;     for (int i = 0, qwe = g[u].size(); i < qwe; ++i)       if (dfs(g[u][i], c[g[u][i]])) {         puts( NO );         return 0;       }     printf( YES n%d n , u + 1);     return 0;   }   