T-T

#include <iostream>
using namespace std;
int main() {
int n, sum;
int a[10000];
int b[10000] = {0};
long long cnt = 0;

cin >> n >> sum;
for (int i = 0; i < n; i++)
{
    cin >> a[i];
}

for (int i = 0; i < n; i++)
{
    for (int j = 0; j < n; j++)
    {
        b[a[i] + a[j]]++;
    }
}
for (int i = 0; i < n; i++)
{
    for (int j = 0; j < n; j++)
    {
        if (sum - a[i] - a[j] > 0)
        {
            cnt += b[sum - a[i] - a[j]];
        }
    }
}    
cout << cnt; 
return 0;

}