Monocarp drew an undirected graph with $$$n$$$ vertices and $$$m$$$ edges. He wants to color each vertex red or blue so that every vertex has at least one neighbor of the opposite color. He needs to calculate the number of colorings that suit him.
Monocarp is a caveman: he knows only the numbers $$$1$$$, $$$2$$$, and "many" (any number greater than $$$2$$$). He does not know about zero, so if there are no valid colorings, his brain melts.
Help Monocarp count the valid colorings in his language. Two colorings are considered different if at least one vertex has a different color in them.
The first line contains an integer $$$t$$$ ($$$1 \le t \le 10^4$$$) — the number of test cases.
The first line of each test case contains two integers $$$n$$$ and $$$m$$$ ($$$3 \le n \le 3 \cdot 10^5$$$; $$$0 \le m \le \min\left(\frac{n(n-1)}{2}, 3 \cdot 10^5\right)$$$) — the number of vertices and edges.
Each of the next $$$m$$$ lines contains two integers $$$u_i$$$ and $$$v_i$$$ ($$$1 \le u_i, v_i \le n$$$) — the numbers of the vertices connected by the $$$i$$$-th edge. The graph has no self-loops or multiple edges.
Additional constraints on the input:
For each test case, print on a separate line:
43 11 23 21 21 33 31 22 31 34 31 22 33 4
Brain Melt2ManyMany
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