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

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

int main(){
	int n, m; cin >> n >> m;
	if (m % 2 == 1){
		cout << 0 << '\n';
		return 0;
	}

	vector<ll> a(n);
	rep(i,0,n){
		cin >> a[i];
		if (a[i] == m) a[i] -= m;
	}
	sort(a.begin(), a.end());

	set<ll> st;	
	rep(i,0,n){
		st.insert(a[i]);
	}

	ll ans = 0;
	rep(i,0,n){
		if (a[i] + m / 2 >= m) continue;
		if (st.find(a[i] + m / 2) == st.end()){
			continue;
		}
		ans += n - 2;
	}

	cout << ans << '\n';
		
}