Score : $300$ points
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.
If the two toys have the same shape, print Yes
; otherwise, print No
.
Input is given from Standard Input in the following format:
$N$ $M$ $A_1$ $B_1$ $\vdots$ $A_M$ $B_M$ $C_1$ $D_1$ $\vdots$ $C_M$ $D_M$
If the two toys have the same shape, print Yes
; otherwise, print No
.
4 4 1 2 1 3 1 4 3 4 1 3 1 4 2 3 3 4
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.
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
No
The two toys do not have the same shape.
8 0
Yes