#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;
 
	unordered_map<int,int> freq;
 
	for(int i=0; i<n; i++){
 
 
		int reqNum1 = target + numbers[i];
		int reqNum2 = numbers[i] - target;
 
		if(freq.find(reqNum1) != freq.end())answer += freq[reqNum1];
		if(freq.find(reqNum2) != freq.end())answer += freq[reqNum2];
 
		freq[numbers[i]]++;
	}
 
	cout<<answer;
 
	return 0;
}

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NyAyCjcgMiAyIDMgMyA1IDU=

7 2
7 2 2 3 3 5 5