#include<fstream>
#include<string.h>
#include<ctype.h>
#include<iostream>
#include<algorithm>
#include<map>
#include<unordered_map>
#include<array>
#include<functional>
#include<deque>
#include<math.h>
#include<unordered_set>
#include<queue>
#include<list>
#include<set>
#include<iomanip>
#include<bitset>
using namespace std;
int i, j, k, l, c, v[1050], nr, max1, min1;
unordered_map<int, int>mp;
unordered_map<int, int>::iterator it, iter;

int main()
{
	//ifstream f("file.in");
	//ofstream g("file.out");
	ifstream f("oite.in");
	ofstream g("oite.out");
	f >> c >> l;
	for (i = 1; i <= c; i++)
		f >> v[i];
	sort(v + 1, v + c + 1);
	for (i = 1; i <= c - 1; i++)
	{
		for (j = i + 1; j <= c; j++)
		{
			it = mp.find(l - v[i] - v[j]);
			if (it != mp.end())
				nr += it->second;

		}
		for (j = 1; j < i; j++)
			mp[v[i] + v[j]]++;
	}
	g << nr;
	return 0;
}