Beautiful Graph

Description:

Input:

The first line contains one integer $$$t$$$ ($$$1 \le t \le 3 \cdot 10^5$$$) — the number of tests in the input.

The first line of each test contains two integers $$$n$$$ and $$$m$$$ ($$$1 \le n \le 3 \cdot 10^5, 0 \le m \le 3 \cdot 10^5$$$) — the number of vertices and the number of edges, respectively. Next $$$m$$$ lines describe edges: $$$i$$$-th line contains two integers $$$u_i$$$, $$$ v_i$$$ ($$$1 \le u_i, v_i \le n; u_i \neq v_i$$$) — indices of vertices connected by $$$i$$$-th edge.

It is guaranteed that $$$\sum\limits_{i=1}^{t} n \le 3 \cdot 10^5$$$ and $$$\sum\limits_{i=1}^{t} m \le 3 \cdot 10^5$$$.

Output:

For each test print one line, containing one integer — the number of possible ways to write numbers $$$1$$$, $$$2$$$, $$$3$$$ on the vertices of given graph so it becomes beautiful. Since answers may be large, print them modulo $$$998244353$$$.

Sample Input:

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

Sample Output:

4
0

Note:

Possible ways to distribute numbers in the first test:

1. the vertex $$$1$$$ should contain $$$1$$$, and $$$2$$$ should contain $$$2$$$;
2. the vertex $$$1$$$ should contain $$$3$$$, and $$$2$$$ should contain $$$2$$$;
3. the vertex $$$1$$$ should contain $$$2$$$, and $$$2$$$ should contain $$$1$$$;
4. the vertex $$$1$$$ should contain $$$2$$$, and $$$2$$$ should contain $$$3$$$.

In the second test there is no way to distribute numbers.