def count(n, arr, k):
	count = 0
	seen = {}
	
	for i in range(n):
		comp = k-arr[i]
		if comp in seen:
			count+=1
		seen[arr[i]] = True
	return count
	
if __name__=="__main__":
	n = int(input())
	k = int(input())
	arr = [int(input()) for _ in range(n)]
	ans = count(n, arr, k)
	print(ans)