#include<iostream>
#include<algorithm>
using namespace std;
int N,A,B,C,ans;unsigned long long z[1000005];
int main(){
	cin>>N>>C;
	for(int i=0;i<N;i++) cin>>z[i] ;
	sort(z,z+N);
	for(int i=0;i<N;i++){
		A=i,B=i+1;
		while(z[B]-z[A]<=C){
			if(z[B]-z[A]==C) ans++;
			B++;
			//cout<<"@#$%^&*"<<A<<" "<<B<<endl;
		}
	}
	cout<<ans;
}