#include <bits/stdc++.h>
using namespace std;
ifstream r("iepuri.in");
ofstream w("iepuri.out");
unordered_map <int, int> m;
int n, sum, v[1030], ans;
int main()
{
    r>>n>>sum;
    for(int i=1;i<=n;i++){
        r>>v[i];
    }
    sort(v+1,v+n+1);
    for(int i=1;i<n;i++)
    {
        for(int j=i+1;j<=n;j++)
        {
            if(v[i]+v[j]>sum){
                break;
            }
            int rest=sum-v[i]-v[j];
            if(m.find(rest)!=m.end()){
                ans+=m[rest];
            }
        }
        for(int j=1;j<i;j++){
            m[v[i]+v[j]]++;
        }
    }
    w<<ans;
    return 0;
}