Skipper the squirrel has recently escaped his human owners, but being a new wild squirrel, Skipper is in dire need of nuts! Luckily for him, his mentor, Nibbles has buried nuts and maps at each of ~N~ locations. Specifically, at location ~i~, Nibbles has hidden a nut and a map to location ~a_i~. So, whenever Skipper is at ~i~, he will collect the nut at that location (if he hadn't collected it before) and follow the map to location ~a_i~, and repeat. Skipper is currently at location ~R~. If Skipper repeats this process indefinitely, can you figure out how many nuts he collects?

Constraints

~1\le N\le 3\times 10^5~

~1\le a_i\le N~

~1\le R\le N~

Input Specification

The first line contains two integers, ~N~ and ~R~.

The second line contains ~N~ integers, the ~i~-th of which corresponds to ~a_i~

Output Specifcation

One line with one integer, the number of nuts Skipper can collect by repeating his process indefinitely

Sample Input

7 4
5 4 1 3 6 4 2

Sample Output

5

Sample Explanation

Skipper starts at location ~4~, where he collects a nut and moves to location ~a_4=3~

At location ~3~, collects a nut at location ~3~ and moves to location ~a_3=1~

Even if Skipper repeats this process indefinitely, he will only visit the locations ~1~, ~3~, ~4~, ~5~, and ~6~. Since he can only collect at most one nut at each location, Skipper can only collect ~5~ nuts.