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.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.HashMap;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author zodiacLeo
 */
public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            int n = in.nextInt();
            int x = in.nextInt();

            HashMap<Long, Long> countMap = new HashMap<>();
            for (int i = 0; i < n; i++)
            {
                long num = in.nextLong();
                Long count = countMap.get(num);
                count = count == null ? 1 : count + 1;
                countMap.put(num, count);
            }

            long result = 0;
            for (Map.Entry<Long, Long> entry : countMap.entrySet())
            {
                long n1 = entry.getKey();
                long count1 = entry.getValue();

                long n2 = n1 ^ x;
                if (countMap.containsKey(n2))
                {
                    long count2 = countMap.get(n2);
                    if (n1 == n2)
                    {
                        result += count1 * (count1 - 1);
                    } else
                    {
                        result += (count1 * count2);
                    }
                }
            }
            out.println(result / 2);
        }

    }
}

