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

int main() {
	int n,target;
	cin>>n>>target;
	
	vector<int> numbers(n);
	
	for(auto& number: numbers){
		cin>>number;
	}
	
	int answer = 0;
	
	for(int i=0; i<n; i++){
		for(int j=i+1; j<n; j++){
			if(numbers[i] - numbers[j] == target)answer++;
		}
	}
	
	cout<<answer;
	
	return 0;
}