#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;
int n , k;
int Male[NMAX] , Female[NMAX];
int NumMale , NumFemale;

long long ans ;

void process()
{
        cin>> n >> k;
        for(int i = 1 ; i <= n ; i++)
        {
                int height;
                cin>>height;

                if(height > 0)   Male[++NumMale] = height;

                if(height <= 0 ) Female[++NumFemale] = -height;
        }

        sort(Male + 1 , Male + NumMale + 1);

        for(int i = 1 ; i <= NumFemale ; i++)
        {
                int l = lower_bound(Male + 1 , Male + NumMale + 1 , Female[i])  - Male;

                int r = upper_bound(Male + 1 , Male + NumMale + 1 , Female[i] + k) - Male - 1;

                if(l <= r )ans += r - l + 1;
        }

        cout<<ans;
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
    cout.tie(nullptr);
    process();
    return 0;
}