#include <cstdio>
#include <vector>
#include <algorithm>
#include <unordered_map>
using namespace std;
unordered_map <int,int> hashin;
int main()
{
    int sol=0,x,suma,n;
    vector <int> v;
    freopen("oite.in","r",stdin);
    freopen("oite.out","w",stdout);
    scanf("%d%d",&n,&suma);
    for(int i=1;i<=n;++i){
        scanf("%d",&x);
        v.push_back(x);
    }
    sort(v.begin(),v.end());
    for(int i=0;i<n;++i){
        for(int j=i+1;j<n;++j)
            sol+=hashin[suma-v[i]-v[j]];
        for(int j=0;j<i;++j)++hashin[v[i]+v[j]];
    }
    printf("%d\n",sol);
    return 0;
}