There are some beautiful girls in Arpa’s land as mentioned before.

Once Arpa came up with an obvious problem:

Given an array and a number x, count the number of pairs of indices i, j (1 ≤ i < j ≤ n) such that <image>, where <image> is bitwise xor operation (see notes for explanation).

<image>

Immediately, Mehrdad discovered a terrible solution that nobody trusted. Now Arpa needs your help to implement the solution to that problem.

Input

First line contains two integers n and x (1 ≤ n ≤ 105, 0 ≤ x ≤ 105) — the number of elements in the array and the integer x.

Second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 105) — the elements of the array.

Output

Print a single integer: the answer to the problem.

Examples

Input

2 3
1 2


Output

1

Input

6 1
5 1 2 3 4 1


Output

2

Note

In the first sample there is only one pair of i = 1 and j = 2. <image> so the answer is 1.

In the second sample the only two pairs are i = 3, j = 4 (since <image>) and i = 1, j = 5 (since <image>).

A bitwise xor takes two bit integers of equal length and performs the logical xor operation on each pair of corresponding bits. The result in each position is 1 if only the first bit is 1 or only the second bit is 1, but will be 0 if both are 0 or both are 1. You can read more about bitwise xor operation here: <https://en.wikipedia.org/wiki/Bitwise_operation#XOR>.

def binarySearch( List , i , j , number ) :
	if i == j : 
		if List[ i ] == number :
			return True
		else :
			return False
	if i > j :
		return False
	mid = ( i + j ) / 2
	if number == List[ mid ] :
		return True
	if number < List[ mid ] :
		return binarySearch( List , i , mid , number )
	return binarySearch( List , mid + 1 , j , number  ) 


if __name__ == "__main__" :
	List = raw_input().split()
	List = [ int( i ) for i in List ]
	List1 = raw_input().split()
	List1 = [ int( i ) for i in List1 ]
	Hash = { i : 0 for i in List1 }
	for i in List1 :
		Hash[ i ] += 1
	counter = 0
	for i in xrange( len( List1 )) :
		offset = 0
		temp = List1[ i ] ^ List[ 1 ] 
		if temp == List1[ i ] :
			offset = 1
		if temp in Hash :
			counter += Hash[ temp ] - offset
	print counter / 2