#include <bits/stdc++.h>
#define IOS ios_base::sync_with_stdio(0);
#define tie cin.tie(0);
#define mp make_pair
#define ll long long
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define zeros(x) ( (x ^ (x - 1)) & x )
#define INF 0x3f3f3f3f
    
using namespace std;

unordered_map < int, int > UM;
ll rs;
int a[1 << 11], n, sum;

int main(){
	IOS tie
    ifstream cin("oite.in");
    ofstream cout("oite.out");
    cin >> n >> sum;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i <= n; i++)
    {
        for (int j = i + 1; j <= n; j++)
            rs += (UM.find(sum - a[i] - a[j]) != UM.end() ? UM[sum - a[i] - a[j]] : 0);
        for (int j = 1; j < i; j++) UM[a[i] + a[j]]++;
    }
    cout << rs;
    cerr << "Fucking time elapsed: " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms" << '\n';
    return 0;
}