#abc288c. [abc288_c]Don’t be cycle

[abc288_c]Don’t be cycle

Problem Statement

You are given a simple undirected graph with NN vertices and MM edges. The vertices are numbered 11 to NN, and the ii-th edge connects vertex AiA_i and vertex BiB_i. Let us delete zero or more edges to remove cycles from the graph. Find the minimum number of edges that must be deleted for this purpose.

What is a simple undirected graph? A simple undirected graph is a graph without self-loops or multi-edges whose edges have no direction.

What is a cycle? A cycle in a simple undirected graph is a sequence of vertices (v0,v1,ldots,vn1)(v_0, v_1, \\ldots, v_{n-1}) of length at least 33 satisfying vineqvjv_i \\neq v_j if ineqji \\neq j such that for each 0leqi<n0 \\leq i < n, there is an edge between viv_i and vi+1bmodnv_{i+1 \\bmod n}.

Constraints

  • 1leqNleq2times1051 \\leq N \\leq 2 \\times 10^5
  • 0leqMleq2times1050 \\leq M \\leq 2 \\times 10^5
  • 1leqAi,BileqN1 \\leq A_i, B_i \\leq N
  • The given graph is simple.
  • All values in the input are integers.

Input

The input is given from Standard Input in the following format:

NN MM A1A_1 B1B_1 A2A_2 B2B_2 vdots\\vdots AMA_M BMB_M

Output

Print the answer.


Sample Input 1

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

Sample Output 1

2

One way to remove cycles from the graph is to delete the two edges between vertex 11 and vertex 22 and between vertex 44 and vertex 55.
There is no way to remove cycles from the graph by deleting one or fewer edges, so you should print 22.


Sample Input 2

4 2
1 2
3 4

Sample Output 2

0

Sample Input 3

5 3
1 2
1 3
2 3

Sample Output 3

1