#include <bits/stdc++.h>
using namespace std;
 
int main() {
	int n ;
	cin>>n;
	int target;
	cin>>target;
	int arr[n];
	for(int i = 0; i< n ; i++){
		cin>>arr[i];
	}
	int count = 0;
	unordered_map<int,int> mpp;
	for(int j = 0; j< n ; j++){
		int r1 = target - arr[j];
		int r2 = target + arr[j];
		if(mpp.count(r1)){
			count += mpp[r1];
		}
		if(mpp.count(r2)){
			count += mpp[r2];
		}
		mpp[arr[j]] = mpp[arr[j]] + 1;
	}
	cout << count;
 
    return 0;
}