Description:
You are given a permutation $$$p_1, p_2, \dots, p_n$$$. A permutation of length $$$n$$$ is a sequence such that each integer between $$$1$$$ and $$$n$$$ occurs exactly once in the sequence.
Find the number of pairs of indices $$$(l, r)$$$ ($$$1 \le l \le r \le n$$$) such that the value of the median of $$$p_l, p_{l+1}, \dots, p_r$$$ is exactly the given number $$$m$$$.
The median of a sequence is the value of the element which is in the middle of the sequence after sorting it in non-decreasing order. If the length of the sequence is even, the left of two middle elements is used.
For example, if $$$a=[4, 2, 7, 5]$$$ then its median is $$$4$$$ since after sorting the sequence, it will look like $$$[2, 4, 5, 7]$$$ and the left of two middle elements is equal to $$$4$$$. The median of $$$[7, 1, 2, 9, 6]$$$ equals $$$6$$$ since after sorting, the value $$$6$$$ will be in the middle of the sequence.
Write a program to find the number of pairs of indices $$$(l, r)$$$ ($$$1 \le l \le r \le n$$$) such that the value of the median of $$$p_l, p_{l+1}, \dots, p_r$$$ is exactly the given number $$$m$$$.
Input Format:
The first line contains integers $$$n$$$ and $$$m$$$ ($$$1 \le n \le 2\cdot10^5$$$, $$$1 \le m \le n$$$) — the length of the given sequence and the required value of the median.
The second line contains a permutation $$$p_1, p_2, \dots, p_n$$$ ($$$1 \le p_i \le n$$$). Each integer between $$$1$$$ and $$$n$$$ occurs in $$$p$$$ exactly once.
Output Format:
Print the required number.
Note:
In the first example, the suitable pairs of indices are: $$$(1, 3)$$$, $$$(2, 2)$$$, $$$(2, 3)$$$ and $$$(2, 4)$$$.