/* 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
	{
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		int k=sc.nextInt();
		int nums[] = new int[n];
		for(int i=0; i<n; i++){
			nums[i]=sc.nextInt();
		}
		
		int res = sumOfPairEqualsK(k,nums);
		System.out.println(res);
		
	}
	
	public static int sumOfPairEqualsK(int k,int []nums){
		HashMap<Integer,Integer> map = new HashMap<>();
		int cnt=0;
		for(int i=0; i<nums.length; i++){
			if(map.containsKey(k - nums[i])){
				cnt++;
			}
			map.put(nums[i],i);
		}
		
		return cnt;
		
	}
}