The undirected graph is given. Find all its articulation points.
The first line contains two positive integers and — the number of vertices and edges respectively.
Each of the next lines contains the description of an edge. The edge number is given with two positive integers — the numbers of the vertices it connects.
Print in the first line the number of articulation points in a given graph. In the next lines print the numbers of the vertices that are articulation points in increasing order.