#include <iostream>
#include <map>
#include <algorithm>
#include <vector>
using namespace std;
 
int main() {
	int n, k;
	cin >> n >> k;
	vector<int> ss(n);
	for(int i = 0; i < n; i++)
		cin >> ss[i];
	sort(ss.begin(), ss.end());
	map<int, int> mp;
	for(int i = 0; i < n; i++)
		mp[ss[i]]++;
	int answer = 0;
	for(int i = 0; i < n; i++) {
		if(!mp[ss[i]])
			continue;
		if(k/2 == ss[i])
			continue;
		answer += mp[ss[i]] * mp[k - ss[i]];
		mp[ss[i]] = mp[k - ss[i]] = 0;
	}
	cout << answer << endl;
	return 0;
}

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