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.*;
import java.util.*;

public class TaskB {
  public static void main(String[] args) {
    TaskB tB = new TaskB();
    BScanner in = new BScanner();
    PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
    tB.solve(in, out);
    out.close();
  }

  public void solve(BScanner in, PrintWriter out) {
    int n = in.nextInt();
    int x = in.nextInt();
    int[] count = new int[1000111];
    long result = 0;
    for (int i = 0; i < n; i++) {
      int val = in.nextInt();
      int target = val ^ x;
      result += count[target];
      count[val]++;
    }
    out.println(result);
  }

  private static class BScanner {
    private BufferedReader input;
    private StringTokenizer st;

    private BScanner() {
      input = new BufferedReader(new InputStreamReader(System.in));
    }

    private String next() {
      while (st == null || !st.hasMoreElements()) {
        try {
          st = new StringTokenizer(input.readLine());
        } catch (IOException e) {
          System.err.println("No more token");
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    private int nextInt() {
      return Integer.parseInt(next());
    }

    private long nextLong() {
      return Long.parseLong(next());
    }

    private double nextDouble() {
      return Double.parseDouble(next());
    }

    private String nextLine() {
      String line = "";
      try {
        line = input.readLine();
      } catch (Exception e) {
        System.err.println("No more lines");
        e.printStackTrace();
      }
      return line;
    }
  }
}
