#include <bits/stdc++.h>

using namespace std;

ifstream in ("oite.in");
ofstream out ("oite.out");

int c, l;

int v[1137];

unordered_map < long long, int > m;

int sorin;

int main()
{
    in >> c >> l;
    for ( int i = 1 ; i <= c ; ++i )
        in >> v[i];
    for ( int i = 2 ; i <= c ; ++i )
    {
        for ( int j = i + 1 ; j <= c ; ++j )
        {
            if ( v[i] + v[j] > l )
                continue;
            sorin += m[l - v[i] - v[j]];
        }
        for ( int j = 1 ; j <= i - 1 ; ++j )
            ++m[v[i] + v[j]];
    }
    out << sorin;
    return 0;
}