Takahashi has $N$ friends. They have nicknames: Friend $1$, Friend $2, \ldots…$, Friend $N$.
One day, Takahashi accidentally let one of his friends, Friend $X$, learn his shameful secret.
For each $i = 1, 2, \ldots, N$, when Friend $i$ learns the secret, he/she will share it with Friend $A_i$, if Friend $A_i$ has not already learned it.
How many of Takahashi's friends will learn the secret in the end?

Input is given from Standard Input in the following format:
$N\ X\\
A_1\ A_2\ \cdots\ A_N$

Print the answer.

$2≤N≤10^5\\
1 \leq X \leq N\\
1 \leq A_i \leq N\\
A_i \neq i$
All values in input are integers.

3

Takahashi's secret will be learned by Friend $1$, Friend $2$, and Friend $3$, as follows.

• One day, Takahashi let Friend $2$ learn the secret.
• Friend $2$ shares it with Friend $1$.
• Friend $1$ shares it with Friend $3$.

In the end, three of his friends learn the secret, so we print $3$.