A vertex in an undirected graph is an articluation point iff removing it disconnects the graph. You have to find the number of articulation point in the given graph.
Input Format
First line contains two integers V and E. Each of next E line contains two integer u and v denoting an edge betwwen vertex u and v.
Output Format
Print the number of articulation point
Constraints
1 <= number of vertices(V) <= 1000 1 <= number of Edges(E) <= V*(V-1)/2;
Example
Input
5 5 1 2 1 3 3 2 3 4 5 4
Output
2