func main()
	var n: int :: cui@inputInt()
	var x: bit64 :: cui@inputInt() $ bit64
	var dic: dict<bit64, int> :: #dict<bit64, int>
	var ans: int :: 0
	for(1, n)
		var a: bit64 :: cui@inputInt() $ bit64
		do ans :+ dic.get(a.xor(x), &)
		do dic.add(a, dic.get(a, &) + 1)
	end for
	do cui@print("\{ans}\n")
end func