Articulation Points

Problem Description

Given an undirected connected graph with $n$ vertices and $m$ edges, output the indices of all articulation points (cut vertices) in ascending order.

Input Format

The first line contains two integers $n, m\ (1 \le n \le 10^5,\ 1 \le m \le 2 \times 10^5)$.

The next $m$ lines each contain two integers $u, v$, denoting an undirected edge. There are no self-loops, but there may be multiple edges.

Output Format

First output one integer: the number of articulation points. Then on the next line, output several numbers in ascending order: the indices of the articulation points.

Sample Input

7 8
1 2
2 3
3 4
2 5
4 5
5 6
5 7
5 7

Sample Output

2
2 5