#include <iostream>
#include <fstream>
#include <algorithm>
#include <unordered_map>

using namespace std;

ifstream fin("oite.in");
ofstream fout("oite.out");

const int N = 1024;
int v[N + 1];

unordered_map <int, int> f;

int main(){
	int n, L;
	fin >> n >> L;
	for(int i = 1; i <= n; i++)
		fin >> v[i];

	int ans = 0;

	for(int i = 1; i <= n; i++){
		for(int j = i + 1; j <= n; j++)
			if(f.find(L - v[i] - v[j]) != f.end())
				ans += f[L - v[i] - v[j]];
		for(int j = 1; j < i; j++){
			if(f.find(v[i] + v[j]) != f.end())
				f[v[i] + v[j]]++;
			else
				f.insert({v[i] + v[j], 1});
		}
	}
	
	fout << ans;

	return 0;	
}