Codeforces764D

Each New Year Timofey and his friends cut down a tree of n vertices and bring it home. After that they paint all the n its vertices, so that the i-th vertex gets colorc_i.

Now it's time for Timofey birthday, and his mother asked him to remove the tree. Timofey removes the tree in the following way: he takes some vertex in hands, while all the other vertices move down so that the tree becomes rooted at the chosen vertex. After that Timofey brings the tree to a trash can.

Timofey doesn't like it when many colors are mixing together. A subtree annoys him if there are vertices of different color in it. Timofey wants to find a vertex which he should take in hands so that there are no subtrees that annoy him. He doesn't consider the whole tree as a subtree since he can't see the color of the root vertex.

A subtree of some vertex is a subgraph containing that vertex and all its descendants.

Your task is to determine if there is a vertex, taking which in hands Timofey wouldn't be annoyed.

Input

The first line contains single integer n (2 ≤ n ≤ 10⁵) — the number of vertices in the tree.

Each of the next n - 1 lines contains two integersu and v (1 ≤ u, v ≤ n,u ≠ v), denoting there is an edge between verticesu and v. It is guaranteed that the given graph is a tree.

The next line contains n integers c₁, c₂, ..., c_n (1 ≤ c_i ≤ 10⁵), denoting the colors of the vertices.

Output

Print "NO" in a single line, if Timofey can't take the tree in such a way that it doesn't annoy him.

Otherwise print "YES" in the first line. In the second line print the index of the vertex which Timofey should take in hands. If there are multiple answers, print any of them.

Example

Input

41 22 33 41 2 1 1

Output

YES2

Input

31 22 31 2 3

Output

YES2

Input

41 22 33 41 2 1 2

Output

NO

题意:n个结点,选一个根节点i,使i的子树颜色相同。

只要两个点的颜色不同，那么根节点必定是两者其中之一。

如果每次不同的都是你，你不做根节点谁做？

#include <iostream>#include <stdio.h>using namespace std;const int AX = 1e5 + 666;int a[AX];int b[AX];int cnt[AX];int c[AX]; int sum = 0;int main(){int n;cin>>n;for(int i=1;i<n;i++)scanf("%d%d",&a[i],&b[i]);for(int i = 1; i <= n; i++)scanf("%d",&c[i]);for(int i=1;i<n;i++){if(c[a[i]] != c[b[i]]){sum++;cnt[a[i]]++;cnt[b[i]]++;}}for(int i = 1; i <= n; i++){if(cnt[i] == sum){             printf("YES\n");printf("%d\n",i);return 0;}}printf("NO\n");return 0;}