/* 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 a[]=new int[n];
		for(int i=0;i<n;i++)
		a[i]=sc.nextInt();
 
		int count=0;
		Map<Integer,Integer> m=new HashMap<>();
		for(int ele:a)
		{
			int cpl=k-ele;
			if(m.containsKey(cpl))
			{
				count+=m.get(cpl);
			}
			m.put(ele,m.getOrDefault(ele,0)+1);
		}
		System.out.println(count);
	}
}

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

NSA0CjMgMiAxIDIgNQ==

5 4
3 2 1 2 5