#abc220h. [abc220_h]Security Camera

[abc220_h]Security Camera

Problem Statement

AtCoder Town has NN intersections and MM roads.
Road ii connects Intersections AiA_i and BiB_i.

Takahashi, the mayor, has decided to install zero or more surveillance cameras at the intersections.
Each intersection can be installed with zero or one surveillance camera.

How many of the 2N2^N ways to install surveillance cameras monitor an even number of roads?

Here, Road ii is said to be monitored when the following condition is satisfied:

a surveillance camera is installed at one or both of Intersections AiA_i and BiB_i.

Constraints

  • 2leqNleq402 \\leq N \\leq 40
  • 1leqMleqfracN(N1)21 \\leq M \\leq \\frac{N(N-1)}{2}
  • 1leqAiltBileqN1 \\leq A_i \\lt B_i \\leq N
  • (Ai,Bi)neq(Aj,Bj)(A_i,B_i) \\neq (A_j,B_j) if ineqji \\neq j.
  • All values in input are integers.

Input

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

3 2
1 2
2 3

Sample Output 1

6

The sets of towns to install surveillance cameras to satisfy the condition are: $\\{ \\} , \\{ 2 \\} , \\{ 1,2 \\} ,\\{1,3\\},\\{2,3\\},\\{1,2,3\\}$.
Note that it is allowed to install no surveillance camera.


Sample Input 2

20 3
5 6
3 4
1 2

Sample Output 2

458752

The town may not be connected.