For an undirected graph $G = \langle V, E \rangle$, its line graph $L(G)$ is also an undirected graph:
- Its vertex set has size $|E|$, where each vertex corresponds uniquely to an edge in the original graph.
- Two vertices are connected by an edge if and only if their corresponding edges in the original graph share a common endpoint (note that there are no self-loops).
Now, given a simple undirected graph $G$ with $n$ vertices and $m$ edges (not necessarily connected), you need to construct a simple undirected graph $H$ with $n'$ vertices and $n$ edges such that $L(H) = G$.
Input
The input contains multiple test cases.
The first line contains an integer $T$, representing the number of test cases. For each test case:
The first line contains two integers $n, m$.
The next $m$ lines each contain two integers $u, v$, describing an edge.
It is guaranteed that $\sum n \leq 3 \times 10^5$ and $\sum m \leq 3 \times 10^6$.
Output
For each test case, if no such $H$ exists, output a single line containing No.
Otherwise, output a single line containing Yes, followed by a line containing two integers $n', m'$, representing the number of vertices and edges of $H$, respectively.
The next $m'$ lines each contain two integers $u, v$, describing an edge.
You must ensure $1 \leq n' \leq 10^6$ and $m'=n$, and the edges must be output in the order of the vertex indices.
If there are multiple valid outputs, you may output any one of them.
Examples
Input 1
5 1 0 2 1 1 2 3 3 1 2 1 3 2 3 4 3 1 2 1 3 1 4 5 6 1 2 2 3 2 4 3 4 3 5 4 5
Output 1
Yes 2 1 1 2 Yes 3 2 1 2 2 3 Yes 3 3 1 2 1 3 2 3 No Yes 5 5 4 5 3 4 1 3 2 3 1 2
Examples 2-11
See the provided files. These samples satisfy the special constraints of their respective subtasks.
Subtasks
For all data, $1 \leq n, \sum n \leq 3 \times 10^5$, $0 \leq m, \sum m \leq 3 \times 10^6$, $1 \leq T \leq 3 \times 10^5$.
| Subtask | $n \leq $ | Special Property | Score |
|---|---|---|---|
| $1$ | $4$ | None | $4$ |
| $2$ | $5$ | $4$ | |
| $3$ | $6$ | $4$ | |
| $4$ | $7$ | $4$ | |
| $5$ | $8$ | $4$ | |
| $6$ | $20$ | $10$ | |
| $7$ | $200$ | $15$ | |
| $8$ | $2 \times 10^4$ | A | $10$ |
| $9$ | None | $15$ | |
| $10$ | $3 \times 10^5$ | A | $10$ |
| $11$ | None | $20$ |
Additional notes:
- (Property A): It is guaranteed that all test cases have a solution, and there exists a graph $H$ satisfying the requirements such that $H$ is a tree.