#arc153f. [arc153_f]Tri-Colored Paths

[arc153_f]Tri-Colored Paths

Problem Statement

You are given a simple connected undirected graph GG with NN vertices and MM edges. The vertices are numbered 11 to NN, and the ii-th edge connects vertices AiA_i and BiB_i.

Find the number of ways to paint each edge of GG in color 11, 22, or 33 so that the following condition is satisfied, modulo 998244353998244353.

  • There is a simple path in GG that contains an edge in color 11, an edge in color 22, and an edge in color 33.

What is a simple path? A simple path is a pair of a sequence of vertices (v1,ldots,vk+1)(v_1, \\ldots, v_{k+1}) and a sequence of edges (e1,ldots,ek)(e_1, \\ldots, e_k) that satisfies the following:

  • ineqjimpliesvineqvji\\neq j \\implies v_i\\neq v_j;
  • edge eie_i connects vertices viv_i and vi+1v_{i+1}.

Constraints

  • 3leqNleq2times1053 \\leq N\\leq 2\\times 10^5
  • 3leqMleq2times1053 \\leq M\\leq 2\\times 10^5
  • 1leqAi,BileqN1 \\leq A_i, B_i \\leq N
  • The given graph is simple and connected.

Input

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

NN MM A1A_1 B1B_1 vdots\\vdots AMA_M BMB_M

Output

Print the number of ways to paint each edge of GG in color 11, 22, or 33 so that the condition in question is satisfied, modulo 998244353998244353.


Sample Input 1

3 3
1 2
1 3
3 2

Sample Output 1

0

Any simple path in GG contains two or fewer edges, so there is no way to satisfy the condition.


Sample Input 2

4 6
1 2
1 3
1 4
2 3
2 4
3 4

Sample Output 2

534

Sample Input 3

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

Sample Output 3

144

Sample Input 4

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

Sample Output 4

1794