# TWO NODES

Time Limit: 24000/12000 MS (Java/Others)

Memory Limit: 65535/32768 K (Java/Others)

## Description

Suppose that G is an undirected graph, and the value of stab is defined as follows:

Among the expression,G-i, -j is the remainder after removing node i, node j and all edges that are directly relevant to the previous two nodes. cntCompent is the number of connected components of X independently.
Thus, given a certain undirected graph G, you are supposed to calculating the value of stab.

## Input

The input will contain the description of several graphs. For each graph, the description consist of an integer N for the number of nodes, an integer M for the number of edges, and M pairs of integers for edges (3<=N,M<=5000).
Please note that the endpoints of edge is marked in the range of [0,N-1], and input cases ends with EOF.

## Output

For each graph in the input, you should output the value of stab.

## Sample Input

4 5
0 1
1 2
2 3
3 0
0 2

## Sample Output

2

zhuyuanchen520

## Source

2013 ACM-ICPC南京赛区全国邀请赛——题目重现