#include <bits/stdc++.h>
using namespace std;
typedef long long i64;

const int SPQR = 1050,  ///Ave Imperator, morituri te salutant!
           MOD = 33037;

struct PII {
    i64 x;
    int y;

    inline PII() { }
    inline PII(i64 _x, int _y) {
        x = _x;
        y = _y;
    }
};

class HMap {
    vector<PII> hsh[MOD];

public:
    inline int& operator[](const i64 &arg) {
        int acc = arg % MOD;
        if(acc<0)
            acc+= MOD;

        for(auto &i: hsh[acc])
            if(i.x == arg)
                return i.y;

        hsh[acc].push_back(PII(arg, 0));
        return hsh[acc].back().y;
    }
};

int v[SPQR];
HMap mp;

int main(void) {
    ifstream fi("oite.in");
    ofstream fo("oite.out");
    int n;
    i64 l, ant;

    ant = 0LL;

    fi >> n >> l;
    for(int i=1; i<=n; ++i)
        fi >> v[i];

    for(int i=1; i<=n; ++i) {
        for(int j=i+1; j<=n; ++j)
            ant += mp[l-v[i]-v[j]];
        for(int j=i-1; j>=1; --j)
            ++ mp[v[i]+v[j]];
    }

    fo << ant << '\n';

    return 0;
}