#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll a[200010];
int main()
{
    ios_base::sync_with_stdio(false);
    ll n,c;
    ll sum=0;
    cin>>n>>c;
    multiset<ll>num;
    for(ll i=0;i<n;i++)
    {
        cin>>a[i];
        num.insert(a[i]);
    }
    for(ll i=0;i<n;i++)
    {
        sum+=num.count(a[i]-c);
    }
    cout<<sum<<endl;
    system("pause");
    return 0;
}