write a go solution for Description:
You are given an integer sequence a_1,a_2,...,a_n.

Find the number of pairs of indices (l,r) (1<=l<=r<=n) such that the value of median of a_l,a_l+1,...,a_r is exactly the given number m.

The median of a sequence is the value of an 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<=l<=r<=n) such that the value of median of a_l,a_l+1,...,a_r is exactly the given number m.

Input Format:
The first line contains integers n and m (1<=n,m<=2*10^5) — the length of the given sequence and the required value of the median.

The second line contains an integer sequence a_1,a_2,...,a_n (1<=a_i<=2*10^5).

Output Format:
Print the required number.

Note:
In the first example, the suitable pairs of indices are: (1,3), (1,4), (1,5), (2,2), (2,3), (2,5), (4,5) and (5,5).. Output only the code with no comments, explanation, or additional text.