tj

#include <bits/stdc++.h>
using namespace std;
int main(){
    int n,c,a[210000];
    cin>>n>>c;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    } 
    sort(a+1,a+n+1);
    int l=1,r=1;
    long long sum=0;
    for(int i=1;i<=n;i++){
        int t=a[i]+c;
        while(l<=n and a[l]<t) l++;
        while(r<=n and a[r]<=t) r++;
        if(a[l]==t and a[r-1]==t)sum+= r-l;
    }cout<<sum;
    return 0;
}