/*
 _____ _             _              _           _
|_   _| |__   ___   / \   _ __  ___| |__  _   _| |
  | | | '_ \ / _ \ / _ \ | '_ \/ __| '_ \| | | | |
  | | | | | |  __// ___ \| | | \__ \ | | | |_| | |
  |_| |_| |_|\___/_/   \_\_| |_|___/_| |_|\__,_|_|

*/
#include<bits/stdc++.h>
#define ll          long long
#define rep(i,a,b)    for(ll int i=a;i<b;i++)
#define vi          vector<ll int>
#define all(a)      (a).begin(),(a).end()
using namespace std;

void solve()
{
    ll n,k;
    cin>>n>>k;
    vi v(n);
    rep(i,0,n)
    {
        cin>>v[i];
    }
    ll ans=0;
    sort(all(v));
    rep(i,0,n)
    {
        ll l=0,r=i-1;
        while(l<=r)
        {
            ll mid=(l+r)/2;
            if(abs(v[mid]-v[i])<=k)
                r=mid-1;
            else
                l=mid+1;
        }
        ans+=i-r-1;
        l=i+1;
        r=n-1;
        while(l<=r)
        {
            ll mid=(l+r)/2;
            if(abs(v[mid]-v[i])<=k)
                l=mid+1;
            else
                r=mid-1;
        }
        ans+=l-i-1;
    }
    cout<<ans/2+n;
    return;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int TESTS=1;
//    cin>>TESTS;
    while(TESTS--)
    {
        solve();
    }
    return 0;
}