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>.
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

/**
 * Created by for on 2017-02-04.
 */
public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        int x = sc.nextInt();

        int arr[] = new int[n];
        Map<Integer, Integer> map = new HashMap<>();
        for (int i = 0; i < n; i++) {
            int num = sc.nextInt();
            arr[i] = num;
            if(map.get(num) == null) {
                map.put(num, 1);
            } else {
                map.put(num, map.get(num) + 1);
            }
        }

        long cnt = 0;
        for (int i = 0; i < n; i++) {
            int a = arr[i]^x;
            if(map.get(a) != null) {
                if(a == arr[i]) cnt+= map.get(a)-1;
                else cnt+= map.get(a);
            }
        }

        System.out.println(cnt/2);
    }
}