#include<iostream>
#include<cmath>
#include<map>
using namespace std;
int main()
{
	long long n,A,C;
	long long ans=0,sum=0;
	map<long long ,long long >m;
	cin>>n>>C;
	for(int i=0;i<n;i++)
	{
		cin>>A;
		if(m.find(A)!=m.end())
		m[A]++;
		else
		m.insert(make_pair(A,1));
	}
	for(map<long long,long long>::iterator j=m.begin();j!=m.end();j++)
	{
		A=j->first;
		ans=abs(A-C);
		if(m.find(ans)!=m.end())
		{
			sum+=m[A]*m[ans];
		}
	}
	cout<<sum;
	return 0;
}