#include <iostream>
#include <fstream>

using namespace std;

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

const int MAX=1100;
const int P=997;
int n,l,cnt,v[MAX],tmp[MAX];
struct nod
{
    int info,cnt;
    nod *urm;
}*H[P];

void mergesort(int st, int dr)
{
    if(st==dr)
        return;
    int m=(st+dr)/2;
    mergesort(st,m);
    mergesort(m+1,dr);
    int k=0;
    int i=st;
    int j=m+1;
    while(i<=m && j<=dr)
        if(v[i]<v[j])
            tmp[++k]=v[i++];
        else
            tmp[++k]=v[j++];
    while(i<=m)
        tmp[++k]=v[i++];
    while(j<=dr)
        tmp[++k]=v[j++];
    for(i=st,j=1;i<=dr;i++,j++)
        v[i]=tmp[j];
}

int aparitii(int x)
{
    int xmod=x%P;
    for(nod *p=H[xmod];p;p=p->urm)
        if(p->info==x)
            return p->cnt;
    return 0;
}

void adauga(int x)
{
    int xmod=x%P;
    if(!aparitii(x))
    {
        nod *u=new nod;
        u->info=x;
        u->cnt=1;
        u->urm=H[xmod];
        H[xmod]=u;
        return;
    }
    for(nod *p=H[xmod];p;p=p->urm)
        if(p->info==x)
        {
            p->cnt++;
            return;
        }
}

int main()
{
    fin >> n >> l;
    for(int i=1;i<=n;i++)
        fin >> v[i];
    mergesort(1,n);
    for(int i=1;i<=n;i++)
    {
        for(int j=i+1;j<=n;j++)
        {
            int s=v[i]+v[j];
            cnt+=aparitii(l-s);
        }
        for(int j=1;j<i;j++)
            adauga(v[i]+v[j]);
    }
    fout << cnt;
    return 0;
}