题目描述
Problem Statement
Takahashi and Aoki each have a toy made by attaching M cords to N balls.
In Takahashi's toy, the balls are numbered $1, \dots, N$, and the i-th cord ties Ball A_i and B_i.
Similarly, in Aoki's toy, the balls are numbered $1, \dots, N$, and the i-th cord ties Ball C_i and D_i.
In each toy, no cord ties a ball to itself, and no two balls are tied by two or more different cords.
Snuke is wondering whether the two toys have the same shape.
Here, they are said to have the same shape when there is a sequence P that satisfies the conditions below.
- P is a permutation of $(1, \dots, N)$.
- For every pair of integers i, j between 1 and N (inclusive), the following holds.
- Balls i and j in Takahashi's toy are tied by a cord if and only if Balls P_i and P_j in Aoki's toy are tied by a cord.
If the two toys have the same shape, print Yes; otherwise, print No.
Input
Input is given from Standard Input in the following format:
N M
A_1 B_1
$\vdots$
A_M B_M
C_1 D_1
$\vdots$
C_M D_M
Output
If the two toys have the same shape, print Yes; otherwise, print No.
Constraints
- $1 \leq N \leq 8$
- $0 \leq M \leq \frac{N(N - 1)}{2}$
- $1 \leq A_i \lt B_i \leq N$ $, (1 \leq i \leq M)$
- $(A_i, B_i) \neq (A_j, B_j)$ $, (i \neq j)$
- $1 \leq C_i \lt D_i \leq N$ $, (1 \leq i \leq M)$
- $(C_i, D_i) \neq (C_j, D_j)$ $, (i \neq j)$
- All values in input are integers.
Sample Input 1
4 4
1 2
1 3
1 4
3 4
1 3
1 4
2 3
3 4
Sample Output 1
Yes
Takahashi's toy is illustrated on the left in the figure below, and Aoki's is illustrated on the right.
The following figure shows that the two toys have the same shape. The condition in the statement is satisfied when P = (3, 2, 1, 4), for example.
Sample Input 2
5 6
1 2
1 3
1 4
3 4
3 5
4 5
1 2
1 3
1 4
1 5
3 5
4 5
Sample Output 2
No
The two toys do not have the same shape.
Sample Input 3
8 0
Sample Output 3
Yes
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分