#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;
    }
};

class InParser {
private:
    FILE *fin;
    char *buff;
    int sp;

    char read_ch() {
        ++sp;
        if (sp == 4096) {
            sp = 0;
            fread(buff, 1, 4096, fin);
        }
        return buff[sp];
    }

public:
    InParser(const char* nume) {
        fin = fopen(nume, "r");
        buff = new char[4096]();
        sp = 4095;
    }

    InParser& operator >> (int &n) {
        char c;
        while (!isdigit(c = read_ch()) && c != '-');
        int sgn = 1;
        if (c == '-') {
            n = 0;
            sgn = -1;
        } else {
            n = c - '0';
        }
        while (isdigit(c = read_ch())) {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }

    InParser& operator >> (long long &n) {
        char c;
        n = 0;
        while (!isdigit(c = read_ch()) && c != '-');
        long long sgn = 1;
        if (c == '-') {
            n = 0;
            sgn = -1;
        } else {
            n = c - '0';
        }
        while (isdigit(c = read_ch())) {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }
};


int v[SPQR];
HMap mp;

int main(void) {
    InParser 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;
}