10. Pairs by Difference

import java.util.Scanner;
import java.util.Arrays;

class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int[] numbers = Arrays
                .stream(scanner.nextLine().split(" "))
                .mapToInt(Integer::parseInt)
                .toArray();

        int difference = Integer.parseInt(scanner.nextLine()),
                count = 0;

        for (int i = 0; i < numbers.length; i++) {
            for (int j = i; j < numbers.length; j++) {
                if (Math.abs(numbers[i] - numbers[j]) == difference) {
                    count++;
                }
            }
        }

        System.out.println(count);
    }
}