#include<bits/stdc++.h>
using namespace std;
#define int long long
const int maxn=1e6+5;
int N,C,a[maxn],ans=0;
int lwbd(int goal,int n){
	int l=1,r=n;
	while(l<r){
		int mid=l+((r-l)>>1);
		if(a[mid]<goal)l=mid+1;
		else r=mid;
	}
	if(a[l]==goal)return l;
	else return -1;
}
int upbd(int goal,int n){
	int l=1,r=n;
	while(l<r){
		int mid=l+((r-l)>>1);
		if(a[mid]>goal)r=mid;
		else l=mid+1;
	}
	return l;
}
signed main(){
	scanf("%lld%lld",&N,&C);
	for(int i=1;i<=N;i++){
		scanf("%lld",&a[i]);
	}
	sort(a+1,a+N+1);
	for(int i=1;i<=N;i++){
		int A=a[i];
		if(A>C){
			//cout<<lwbd(A-C)<<' '<<upbd(A-C)<<'\n';
			if(lwbd(A-C,N)==-1)continue;
			else ans+=(upbd(A-C,N)-lwbd(A-C,N));
		}
	}
	printf("%lld",ans);
	return 0;
}