# TWO NODES

Time Limit: 10000 MS

Memory Limit: 65535 KB

## 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(X)  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

Input consists of multiple cases.

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


None

## Source

2013 ACM-ICPC China Nanjing Invitational Prog