Codeforces Round 295 (Div. 1)
E
Cycling City
Codeforces
3100
原题
← D→
翻译中…

You are organizing a cycling race on the streets of the city. The city contains $*n*$ junctions, some pairs of them are connected by roads; on each road you can move in any direction. No two roads connect the same pair of intersections, and no road connects the intersection with itself.

翻译中…

You want the race to be open to both professional athletes and beginner cyclists, and that's why you will organize the race in three nominations: easy, moderate and difficult; each participant will choose the more suitable nomination. For each nomination you must choose the route — the chain of junctions, consecutively connected by roads. Routes must meet the following conditions:

翻译中…
  • all three routes should start at the same intersection, and finish at the same intersection (place of start and finish can't be the same);
  • to avoid collisions, no two routes can have common junctions (except for the common start and finish), and can not go along the same road (irrespective of the driving direction on the road for those two routes);
  • no route must pass twice through the same intersection or visit the same road twice (irrespective of the driving direction on the road for the first and second time of visit).
翻译中…

Preparing for the competition is about to begin, and you need to determine the routes of the race as quickly as possible. The length of the routes is not important, it is only important that all the given requirements were met.

翻译中…

Input

翻译中…

The first line contains two integers $*n*$ and $*m*$ ($1 ≤ *n*, *m* ≤ 2·10^{5}$) — the number of intersections and roads, respectively.

翻译中…

The following $*m*$ lines contain two integers — the numbers of the intersections connected by a road (the intersections are numbered starting with 1). It is guaranteed that each pair of intersections is connected by no more than one road, and no road connects the intersection to itself.

翻译中…

Please note that it is not guaranteed that you can get from any junction to any other one by using the roads.

翻译中…

Output

翻译中…

If it is possible to create the routes, in the first line print "YES". In the next three lines print the descriptions of each of the three routes in the format "$*l*$ $*p*_{1}$ ... $*p*_{*l*}$", where $*l*$ is the number of intersections in the route, and $*p*_{1}, ..., *p*_{*l*}$ are their numbers in the order they follow. The routes must meet all the requirements specified in the statement.

翻译中…

If it is impossible to make the routes in accordance with the requirements, print NO.

翻译中…

样例

Input #1
4 4
1 2
2 3
3 4
4 1
Output #1
NO
InputCopy OutputCopy
Input #2
5 6
1 2
1 3
1 4
2 5
3 5
4 5
Output #2
YES
3 5 4 1
3 5 3 1
3 5 2 1
InputCopy OutputCopy
题目信息
题号
521E
时间限制
2 s
内存限制
256 MB
标签
DFS 及类似
图论

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。