/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		int arr[] = new int[n];
		for(int i=0; i<n ; i++){
			arr[i] = sc.nextInt();
		}
 
		HashMap<Integer,Integer> hmap = new HashMap<>();
        int count=0;
        for(int i=0; i<n; i++){
            int num = k-arr[i];
            if(hmap.containsKey(num)){
                int freq = hmap.getOrDefault(num, 0);
                count+=freq;
            }
            hmap.put(arr[i], hmap.getOrDefault(arr[i], 0)+1);
        }
        System.out.println(count);
	}
}

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42 43
9 7 53 41 4 97 75 30 54 61 9 8 14 50 95 38 12 38 44 2 78 71 97 67 10 4 68 43 47 56 35 7 62 39 47 17 36 21 46 41 34 7