#include<bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops,inline")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define fast ios_base::sync_with_stdio(0);f.tie(0);g.tie(0);
#define setinf(x) memset(x,0x3f3f3f3f,sizeof(x));
#define set0(x) memset(x,0,sizeof(x));
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define INF 0x3f3f3f3f
#define vi vector<int>
#define ll long long
#define vll vector<ll>
#define pb push_back
#define fi first
#define se second
#define DD 100001
#define nl '\n'
using namespace std;
const string file="oite";
ifstream f(file+".in");
ofstream g(file+".out");
//#define f cin
//#define g cout
int n,l,v[1111];
ll r;
unordered_map<int,int> mp;
int main(){
    f>>n>>l;
    for (int i=1; i<=n; ++i) f>>v[i];
    for (int i=1; i<=n; ++i) {
        for (int j=i+1; j<=n; ++j)
            if (mp.find(l-v[i]-v[j])!=mp.end()) r+=mp[l-v[i]-v[j]];
        for (int j=1; j<i; ++j) mp[v[i]+v[j]]++;
    }
    g<<r;
    system("pause");
    return 0;
}