#include <stdio.h>
#include <map>
#define MAXN 1024

int v[MAXN];
std::map <int, int> f;

int main()
{
    FILE *fin, *fout;
    fin=fopen("oite.in", "r");
    int i,j,n,sum;
    long long rez=0;
    fscanf(fin, "%d%d", &n, &sum);
    for(i=0; i<n; i++){
      fscanf(fin, "%d", &v[i]);
    }
    fclose(fin);
    for(i=0; i<n; i++){
      for(j=i+1; j<n; j++){
        rez+=f[sum-v[i]-v[j]];
      }
      for(j=0; j<i; j++){
        f[v[i]+v[j]]++;
      }
    }
    fout=fopen("oite.out", "w");
    fprintf(fout, "%lld", rez);
    fclose(fout);
    return 0;
}