#include <fstream>
#include <unordered_map>


using namespace std;


ifstream cin("oite.in");
ofstream cout("oite.out");


const int NMAX = 1024;


unordered_map <int, int> frecventa;
int n, l, a[NMAX], answer;


void read() {
	cin >> n >> l;
	for (int index = 0; index < n; ++index) {
		cin >> a[index];
	}
}


void solve() {
	for (int index1 = 1; index1 < n; ++index1) {
		for (int index2 = index1 + 1; index2 < n; ++index2) {
			answer += frecventa[l - a[index1] - a[index2]];
		}
		for (int index2 = index1 - 1; index2 >= 0; --index2) {
			++frecventa[a[index1] + a[index2]];
		}
	}
}


void display() {
	cout << answer;
}


int main() {
	read();
	solve();
	display();
	return 0;
}