Problem Description

Given a permutation of $1,2,...,n$, count how many contiguous subsequences of odd length have the median equal to $b$. The median is the number that lies in the middle after sorting all elements in nondecreasing order.

Input Format

The first line contains two positive integers $n$ and $b$. The second line contains a permutation of $1,2,...,n$.

Output Format

Output a single integer: the number of contiguous subsequences whose median is $b$.

7 4
5 7 2 4 3 1 6 

4

Hint

Constraints

For $30\%$ of the testdata, $n \le 100$；

For $60\%$ of the testdata, $n \le 1000$；

For $100\%$ of the testdata, $n \le 100000,1 \le b \le n$。

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