[CHOPSTICKS]

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class type {
    public static void main(String[] args) throws IOException {
        BufferedReader b = new BufferedReader(new InputStreamReader(System.in));
        String[] input = b.readLine().split(" ");
        int n = Integer.parseInt(input[0]);
        int d = Integer.parseInt(input[1]);
        int[] sticks = new int[n];
        for (int i = 0; i < n; i++) {
            sticks[i] = Integer.parseInt(b.readLine());
        }
        sort(sticks);
        int result = solve(sticks, d);
        System.out.println(result);
    }

    private static void sort(int[] a) {
        // TODO Auto-generated method stub
        for (int i = 0; i < a.length - 1; i++) {
            for (int j = i + 1; j < a.length; j++) {
                if (a[i] > a[j]) {
                    int t = a[i];
                    a[i] = a[j];
                    a[j] = t;
                }
            }
        }
    }

    private static int solve(int[] sticks, int d) {
        // TODO Auto-generated method stub
        int numPair = 0;
        for (int i = 0; i < sticks.length - 1;) {
            if (sticks[i] >= sticks[i + 1] - d) {
                numPair++;
                i += 2;
            } else {
                i += 1;
            }
        }
        return numPair;
    }

}