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.io.OutputStream;
import java.io.PrintWriter;
import java.util.Scanner;
import java.io.InputStream;
import java.util.HashSet;
import java.util.Set;
import java.util.HashMap;
import java.util.Map;

public class Main {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        int n = in.nextInt();
        int x = in.nextInt();
        long result = 0;

        // <expected value, count>
        Map<Integer, Long> valueMap = new HashMap<>();
        Set<Integer> processed = new HashSet<>();

        for (int i = 0; i < n; i++) {
            int nextInt = in.nextInt();
            if (valueMap.containsKey(nextInt)) {
                valueMap.put(nextInt, valueMap.get(nextInt) + 1L);
            } else {
                valueMap.put(nextInt, 1L);
            }
        }
        for (Integer currValue : valueMap.keySet()) {
            if (!processed.contains(currValue)) {
                processed.add(currValue);
                int expected = currValue ^ x;
                if (currValue == expected) {
                    long count1 = valueMap.get(currValue);
                    result += count1 * (count1 - 1) / 2;
                } else if (valueMap.containsKey(expected)) {
                    long count1 = valueMap.get(currValue);
                    long count2 = valueMap.get(expected);
                    result += count1 * count2;  
                    processed.add(expected);
                }
            }
        }

        out.print(result);
        out.close();
    }

}