农夫约翰将他的 N 头奶牛排成一排，以测量它们的身高。
奶牛 i 的高度为 Hi 纳米。
他想拍摄一张连续的奶牛序列的照片，以便参加县博览会上的一次牛摄影比赛。
博览会对所有提交的照片有一个非常奇怪的规则：
当照片中的这一组奶牛的中位数高度至少为某个阈值 X 时，该照片才能算作有效作品。
我们将数组 A[0…K] 的中位数定义为将 A 升序排序后的 A[ceiling(K/2)]。
其中 ceiling(K/2) 表示 K/2 上取整。
例如，{7,3,2,6} 的中位数是 6，{5,4,8} 的中位数是 5。
请帮助约翰计算，共有多少不同的连续奶牛序列的照片可以满足参赛要求。
输入格式
第一行包含两个整数 N 和 X。
接下来 N 行，每行包含一个整数 Hi。
输出格式
输出满足中位数至少为 X 的连续奶牛序列数量。
数据范围
1≤N≤105,
1≤Hi,X≤1e9
输入样例：
4 6
10
5
6
2
输出样例：
7
样例解释
满足参赛要求的连续奶牛序列为：
{10}, {6}, {10, 5}, {5, 6}, {6, 2}, {10, 5, 6}, {10, 5, 6, 2}
Problem 1: Above the Median [Brian Dean]
Farmer John has lined up his N (1 <= N <= 100,000) cows in a row to measure
their heights; cow i has height H_i (1 <= H_i <= 1,000,000,000)
nanometers--FJ believes in precise measurements! He wants to take a picture
of some contiguous subsequence of the cows to submit to a bovine
photography contest at the county fair.
The fair has a very strange rule about all submitted photos: a photograph
is only valid to submit if it depicts a group of cows whose median height
is at least a certain threshold X (1 <= X <= 1,000,000,000).
For purposes of this problem, we define the median of an array A[0...K] to
be A[ceiling(K/2)] after A is sorted, where ceiling(K/2) gives K/2 rounded
up to the nearest integer (or K/2 itself, it K/2 is an integer to begin
with). For example the median of {7, 3, 2, 6} is 6, and the median of {5,
4, 8} is 5.
Please help FJ count the number of different contiguous subsequences of his
cows that he could potentially submit to the photography contest.
PROBLEM NAME: median
INPUT FORMAT:
* Line 1: Two space-separated integers: N and X.
* Lines 2..N+1: Line i+1 contains the single integer H_i.
SAMPLE INPUT (file median.in):
4 6
10
5
6
2
INPUT DETAILS:
FJ's four cows have heights 10, 5, 6, 2. We want to know how many
contiguous subsequences have median at least 6.
OUTPUT FORMAT:
* Line 1: The number of subsequences of FJ's cows that have median at
least X. Note this may not fit into a 32-bit integer.
SAMPLE OUTPUT (file median.out):
7
OUTPUT DETAILS:
There are 10 possible contiguous subsequences to consider. Of these, only 7
have median at least 6. They are {10}, {6}, {10, 5}, {5, 6}, {6, 2}, {10,
5, 6}, {10, 5, 6, 2}.