#include<map>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
map<long long,int>ma;
long long n,c,ans;
long long num[200010];
int main(){
    scanf("%lld%lld",&n,&c);
    for(int i=1;i<=n;i++){
        scanf("%lld",&num[i]);
        ma[num[i]]++;
    }
    for(int i=1;i<=n;i++)
        if(ma[num[i]+c])
            ans+=ma[num[i]+c];
    cout<<ans;
}