#include<bits/stdc++.h>
using namespace std;

const int N = 2e5+11;

long long n, c;
long long a[N];
long long ans;
unordered_map<long long, long long> b;

int main(){
	cin>>n>>c;
	for(long long i=0;i<n;i++){
		scanf("%lld",&a[i]);
		b[a[i]] ++;
	}
	sort(a, a + n);
	for(long long i=n-1;a[i]>=c;i--) if(b[a[i] - c]) ans += b[a[i] - c];
	cout<<ans<<endl;
	return 0;
}