#include <stdio.h>
#include <ext/hash_map>
#include <vector>
using namespace std;

#define in "oite.in"
#define out "oite.out"
#define dim 1025
using namespace __gnu_cxx;

int N, L, total=0;
vector<int> C;
hash_map<unsigned,unsigned> M;
hash_map<unsigned,unsigned> W;

int main()
{
    freopen(in,"r",stdin);
    freopen(out,"w",stdout);
    
    int t;
    scanf("%d%d", &N, &L);
    for ( int i = 1; i <= N; i++ )
    {
        scanf("%d", &t);
        if ( !W[t] ) C.push_back(t), W[t] += 1;
        else         W[t] += 1;
    }
    
    for ( int i = 2; i < C.size(); i++ )
    {
        for ( int j = 0; j < i-1; j++ )
        {
            M[C[i-1]+C[j]] += W[C[i-1]] * W[C[j]] - 1;
        }
        
        int K = L - C[i];
        
        for ( int j = i+1; j < C.size(); j++ )
            total += M[K-C[j]]; 
    }
    
    printf("%d", total);
}