CF742B.Arpa’s obvious problem and Mehrdad’s terrible solution

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 , where is bitwise xor operation (see notes for explanation).

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

First line contains two integers $n$ and $x$ ( $1<=n<=10^{5},0<=x<=10^{5}$ ) — the number of elements in the array and the integer $x$ .

Second line contains $n$ integers $a_{1},a_{2},...,a_{n}$ ( $1<=a_{i}<=10^{5}$ ) — the elements of the array.

Print a single integer: the answer to the problem.

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

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

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.