#include <fstream>
#include <climits>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <bitset>
#include <map>
#include <cstring>
#include <algorithm>

#define NMAX 1003


using namespace std;


FILE* fin, * fout;

int n;
long long int lana;
int v[NMAX];
map<int, int>hashi;


int main()
{
	fin = fopen("oite.in", "r");
	fout = fopen("oite.out", "w");

	fscanf(fin, "%d %d", &n,&lana);
	for (int i = 1; i <= n; i++)
	{
		fscanf(fin, "%d", &v[i]);
	}
	

	sort(v + 1, v + n + 1);//sortez lana crescator

	int sol=0;
	for (int i = 1; i < n; i++)
	{
		
		for (int j = i + 1; j <= n; j++)
		{
			if (v[i] + v[j] > lana)
			{
				break;
			}
			//incerc sa vad daca cele 2 oi i si j pot sa le pun la altele 2 sa formez o pereche
			auto itr = hashi.find(lana - v[i] - v[j]);
			if (itr != hashi.end())
			{
				sol += itr->second;
			}
			
		}
		//imi fac pereche automat cu oile precedente si i
		for (int j = 1; j < i; j++)
		{
			auto itr = hashi.find( v[i] + v[j]);
			if (itr != hashi.end())
			{
				itr->second++;
			}
			else {
				hashi.insert({ v[i] + v[j] ,1 });
			}
		}
	}
	fprintf(fout, "%d", sol);
	return 0;
}