Given a simple, undirected graph with n vertices and m edges,. Find all articulation points.
### Input
- The first line contains 2 integers n,m.
- The next m lines, each line contains two integers u,v, there is an edge between u and v.
### Output
- The first line, print the number of articulation points, the second line print the articulation points in ascending order.
### Constraints
- 1≤n,m≤105.
- 1≤u,v≤n.
### Example
Input:
651323344546
Output:
234