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    import java.io.*;
    import java.math.*;
    import java.security.*;
    import java.text.*;
    import java.util.*;
    import java.util.concurrent.*;
    import java.util.function.*;
    import java.util.regex.*;
    import java.util.stream.*;
    import static java.util.stream.Collectors.joining;
    import static java.util.stream.Collectors.toList;
    
    class Result {
    
        /*
         * Complete the 'pairs' function below.
         *
         * The function is expected to return an INTEGER.
         * The function accepts following parameters:
         *  1. INTEGER k
         *  2. INTEGER_ARRAY arr
         */
    
        public static int pairs(int k, List<Integer> arr) {
        // Write your code here
      Set<Integer> set = new HashSet<>();
            int count = 0;
            for (int num : arr) {
                if (set.contains(num - k)) count++;
                if (set.contains(num + k)) count++;
                set.add(num);
            }
            return count;
        }
        }
    
    public class Solution {
        public static void main(String[] args) throws IOException {
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
            BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
    
            String[] firstMultipleInput = bufferedReader.readLine().replaceAll("\\s+$", "").split(" ");
    
            int n = Integer.parseInt(firstMultipleInput[0]);
    
            int k = Integer.parseInt(firstMultipleInput[1]);
    
            List<Integer> arr = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
                .map(Integer::parseInt)
                .collect(toList());
    
            int result = Result.pairs(k, arr);
    
            bufferedWriter.write(String.valueOf(result));
            bufferedWriter.newLine();
    
            bufferedReader.close();
            bufferedWriter.close();
        }
    }