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

#define ll long long
#define cpy(a,b) copy(begin(a),end(a),begin(b))
#define ld long double
#define dot(x) fixed<<setprecision(x)
#define foru(a,b,c) for(ll a=b;a<=c;a++)

ll n,c,p[1000005],cnt[1000005],b[2000005];

int main(){
    freopen("Triplets.in" ,"r",stdin );
    freopen("Triplets.out","w",stdout);
    ios::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    cin>>n>>c;
    foru(i,1,n){
        cin>>p[i];
        cnt[p[i]]++;
    }
    sort(p+1,p+n+1);
    ll ans=n*(n-1)*(n-2)/6,b1=0,b2=0;
    foru(i,1,n){
        b[i]=p[i];
    }
    foru(i,1,n){
        b[i+n]=p[i]+c;
    }
    ll r=0;
    foru(i,1,n){
        if(r<i)r=i;
        while(r<2*n){
            ll tmp=b[r]-b[i];
            if(tmp*2<c){
                r++;
            }else{
                break;
            }
        }
        ll k=r-i-1;
        if(k>=2){
            b1+=k*(k-1)/2;
        }
    }
    if(c%2==0){
        ll c2=c/2,tmp;
        foru(i,0,c2-1){
            ll u=cnt[i],v=cnt[i+c2];
            if(u>0&&v>0){
                tmp=n-u-v;
                b2+=u*v*tmp+(u*(u-1)/2)*v+u*(v*(v-1)/2);
            }
        }
    }
    cout<<ans-b1-b2;
    return 0;
}