#include<iostream>
#include<algorithm>
using namespace std;
int n,x,a[1<<17];
main(){
	cin>>n>>x;
	for(int i=0;i<n;i++)cin>>a[i];
	sort(a,a+n);
	long c=0;
	for(int i=0;i<n;i++)c+=upper_bound(a,a+n,x-a[i])-lower_bound(a,a+n,x-a[i]);
	cout<<c<<endl;
}