package codeforces;

import java.util.*;

public class CodeForces_764C_Timofey_and_a_tree {

       static final int N=(int) (2e5+10);

       @SuppressWarnings("unchecked")

       static ArrayList<Integer> a[]=new ArrayList[N];

       static int book[]=new int[N];

       static int c[]=new int[N];

       static void dfs(int u,int fa)

       {

           int v;

           for(int i=0; i<a[u].size(); i++)

           {

               v=(int) a[u].get(i);

               if(v!=fa)

               {

                   dfs(v,u);

                   if(c[v]!=c[u])

                   {

                       book[u]++;

                       book[v]++;

                   }

               }

           }

       }

       static void solve(){

           Scanner sc=new Scanner(System.in);

           while(sc.hasNext()){

               int n = sc.nextInt();

               int u,v;

               for(int i=1; i<n; i++)

               {

                   u=sc.nextInt();

                   v=sc.nextInt();

                   if(a[u]==null) a[u]=new ArrayList<Integer>();

                   if(a[v]==null) a[v]=new ArrayList<Integer>();

                   a[u].add(v);

                   a[v].add(u);

               }

               Arrays.fill(book,0);

               for(int i=1; i<=n; i++) c[i]=sc.nextInt();

               dfs(1,-1);

               int ans2=n,flag=0,maxx=0;

               for(int i=1; i<=n; i++)

               {

                   if(book[i]>maxx)

                   {

                       maxx=book[i];

                       ans2=i;

                   }

               }

               for(int i=0; i<a[ans2].size(); i++)

               {

                   v=(int)a[ans2].get(i);

                   book[ans2]-=book[v];

                   book[v]=0;

               }

               if(book[ans2]!=0) System.out.println("NO");

               else

               {

                   for(int i=1; i<=n; i++)

                   {

                       if(book[i]!=0)

                       {

                           flag=1;

                           break;

                       }

                   }

                   if(flag==1) System.out.println("NO");

                   else

                       System.out.println("YES\n"+ans2);

               }

           }

       }

       public static void main(String args[]){

           solve();

       }

}