func main()
	var n: int :: cui@inputInt()
	var x: int :: cui@inputInt()
	var mp: dict<int, int> :: #dict<int, int>
	for i(0, n - 1)
		var a: int :: cui@inputInt()
		do mp.add(a, mp.get(a, &) + 1)
	end for
	var keys: []int
	block
		var keyList: List :: #List
		class List()
			+var li: list<int>
			*func ctor()
				do me.li :: #list<int>
			end func
		end class
		do mp.forEach(callback, keyList $ kuin@Class)
		func callback(key: int, value: int, data: kuin@Class): bool
			do(data $ List).li.add(key)
			ret true
		end func
		do keys :: keyList.li.toArray()
	end block
	var ans: int :: 0
	for i(0, ^keys - 1)
		var k: int :: keys[i]
		var a: int :: x - k
		var nk: int :: mp.get(k, &)
		var na: int :: mp.get(a, &)
		do ans :+ nk * na
	end for
	do cui@print("\{ans}\n")
end func