Problem9241--ABC292 —— D - Unicyclic Components

9241: ABC292 —— D - Unicyclic Components

[Creator : ]
Time Limit : 1.000 sec  Memory Limit : 512 MiB

Description

### Problem Statement

You are given an undirected graph with $N$ vertices numbered $1$ to $N$ and $M$ edges numbered $1$ to $M$. Edge $i$ connects vertex $u_i$ and vertex $v_i$.

Determine whether every connected component in this graph satisfies the following condition.

-   The connected component has the same number of vertices and edges.

Input

### Input

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

```
$N$ $M$
$u_1$ $v_1$
$\vdots$
$u_M$ $v_M$
```

Output

### Output

If every connected component satisfies the condition, print `Yes`; otherwise, print `No`.

Constraints

### Constraints

-   $1 \leq N \leq 2 \times 10^5$
-   $0 \leq M \leq 2 \times 10^5$
-   $1 \leq u_i \leq v_i \leq N$
-   All values in the input are integers.

Sample 1 Input

3 3
2 3
1 1
2 3

Sample 1 Output

Yes
The graph has a connected component formed from just vertex 1, and another formed from vertices 2 and 3.
The former has one edge (edge 2), and the latter has two edges (edges 1 and 3), satisfying the condition.

Sample 2 Input

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

Sample 2 Output

Yes

Sample 3 Input

13 16
7 9
7 11
3 8
1 13
11 11
6 11
8 13
2 11
3 3
8 12
9 11
1 11
5 13
3 12
6 9
1 10

Sample 3 Output

No

Source/Category