import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) throws Exception  {

		//BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		Scanner inr = new Scanner (System.in);
		int n = inr.nextInt();
		int k = inr.nextInt();
		int num[] = new int[n];
		for(int i=0;i<n;i++){
			num[i] = inr.nextInt();
		}
		Arrays.sort(num);
		int count = 0;
		for(int i=0;i<n;i++){
			for(int j=i+1;j<n;j++){
				if(num[j] - num[i] == k || num[i] - num[j] == k){
					count++;
				}
				else if(num[j] - num[i] > k || num[i] - num[j] > k){
					break;
				}
			}
		}
		System.out.println(count);
	}

}