#描述#
We say that an undirected graph is connected if,for every pair of nodes u and v,there is a path from u to v.
Hence the problem is given a undirected but connected graph,output the maximum edges which can be deleted left the graph still connected.

#格式#
##输入格式##
The first line is the number of vertexes N(1&lt=N&lt=100) and the number of edges M. A blank stands between them.The vertexes noded by integer 1..N.Then the following M lines,with two integers v1 and v2 represented one edge. A blank also stands between v1 and v2(v1&lt&gtv2).There will not be any duplicate edges.
Be careful for more cases.

##输出格式##
print only a line for each case with the number of maximum edges deledted.

#样例1#
##样例输入1##

3 4
1 2
2 3
1 3
2 3

##样例输出1##

2

#限制#
1000ms
32768KB

#提示#

#来源#