#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
using namespace std;
const int MAXN=2*10e5+10;
int p_ans;
int pre=-1;
int D[MAXN];
int a,b,c,N,tosearch;
unsigned long long ans=0;
bool cmp(int a,int b)
{
    return a<b;
}

void find(int l,int r)
{
    int mid=(l+r)/2;
    if(l>=r)
    {
        if(D[l]!=tosearch) return;
        else
        {
            while(D[l]==tosearch)
            {
            ++l;
            ++ans;
            ++p_ans;
            }
            return;
        }
    }
    if(D[mid]<tosearch) find(mid+1,r);
    else find(l,mid);
}

int main()
{
    memset(D,0,sizeof D);
    cin>>N>>c;
    for(int i=1;i<=N;++i)
    {
        scanf("%d",&D[i]);
    }
    sort(D+1,D+N+1,cmp);
    for(int i=1;i<=N;++i)
    {
        if(D[i]==pre)
        {
            ans+=p_ans;
            continue;
        }
        p_ans=0;
        tosearch=D[i]+c;
        if(c>0) find(i,N);
        else find(1,i-1);
        pre=D[i];
    }

    printf("%d",ans);
    return 0;
}