Codeforces Round 150 (Div. 2)
D
Hydra
Codeforces
未评级
原题
← CE →
翻译中…

One day Petya got a birthday present from his mom: a book called "The Legends and Myths of Graph Theory". From this book Petya learned about a hydra graph.

翻译中…

A non-oriented graph is a hydra, if it has a structure, shown on the figure below. Namely, there are two nodes $*u*$ and $*v*$ connected by an edge, they are the hydra's chest and stomach, correspondingly. The chest is connected with $*h*$ nodes, which are the hydra's heads. The stomach is connected with $*t*$ nodes, which are the hydra's tails. Note that the hydra is a tree, consisting of $*h* + *t* + 2$ nodes.

翻译中…

image

翻译中…

Also, Petya's got a non-directed graph $*G*$, consisting of $*n*$ nodes and $*m*$ edges. Petya got this graph as a last year birthday present from his mom. Graph $*G*$ contains no self-loops or multiple edges.

翻译中…

Now Petya wants to find a hydra in graph $*G*$. Or else, to make sure that the graph doesn't have a hydra.

翻译中…

Input

翻译中…

The first line contains four integers $*n*$, $*m*$, $*h*$, $*t*$ ($1 ≤ *n*, *m* ≤ 10^{5}$, $1 ≤ *h*, *t* ≤ 100$) — the number of nodes and edges in graph $*G*$, and the number of a hydra's heads and tails.

翻译中…

Next $*m*$ lines contain the description of the edges of graph $*G*$. The $*i*$-th of these lines contains two integers $*a*_{*i*}$ and $*b*_{*i*}$ ($1 ≤ *a*_{*i*}, *b*_{*i*} ≤ *n*$, $*a* ≠ *b*$) — the numbers of the nodes, connected by the $*i*$-th edge.

翻译中…

It is guaranteed that graph $*G*$ contains no self-loops and multiple edges. Consider the nodes of graph $*G*$ numbered with integers from 1 to $*n*$.

翻译中…

Output

翻译中…

If graph $*G*$ has no hydra, print "NO" (without the quotes).

翻译中…

Otherwise, in the first line print "YES" (without the quotes). In the second line print two integers — the numbers of nodes $*u*$ and $*v*$. In the third line print $*h*$ numbers — the numbers of the nodes that are the heads. In the fourth line print $*t*$ numbers — the numbers of the nodes that are the tails. All printed numbers should be distinct.

翻译中…

If there are multiple possible answers, you are allowed to print any of them.

翻译中…

Note

翻译中…

The first sample is depicted on the picture below:

翻译中…

image

翻译中…

样例

Input #1
9 12 2 3
1 2
2 3
1 3
1 4
2 5
4 5
4 6
6 5
6 7
7 5
8 7
9 1
Output #1
YES
4 1
5 6
9 3 2
InputCopy OutputCopy
Input #2
7 10 3 3
1 2
2 3
1 3
1 4
2 5
4 5
4 6
6 5
6 7
7 5
Output #2
NO
InputCopy OutputCopy
题目信息
题号
244D
时间限制
2 s
内存限制
256 MB

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。