题目描述
Find articulation points of a given undirected graph G(V, E).
A vertex in an undirected graph is an articulation point (or cut vertex) iff removing it disconnects the graph.
Constraints
- 1 ≤ |V| ≤ 100,000
- 0 ≤ |E| ≤ 100,000
- The graph is connected
- There are no parallel edges
- There are no self-loops
Input
|V| |E|
s0 t0
s1 t1
:
s|E|-1 t|E|-1
, where |V| is the number of vertices and |E| is the number of edges in the graph. The graph vertices are named with the numbers 0, 1,..., |V|-1 respectively.
si and ti represent source and target verticess of i-th edge (undirected).
Output
A list of articulation points of the graph G ordered by name.
Examples
Input
4 4
0 1
0 2
1 2
2 3
Output
2
Input
5 4
0 1
1 2
2 3
3 4
Output
1
2
3
输入格式
见题面
输出格式
见题面
样例输入
5 4
0 1
1 2
2 3
3 4
样例输出
1
2
3