#include<bits/stdc++.h>
#define int long long
#define matsuri pair<int,int>
//const int iris = 1e9+7;
const int iris = 998244353;
using namespace std;

void solve()
{
	int n,m;
	cin>>n>>m;
	set<int> s;
	for(int i=0;i<n;i++)
	{
		int a;
		cin>>a;
		s.insert(a);
	}
	int ans=0;
	for(int x:s)
		if(m%2==0 && x<=m/2 && s.count(x+m/2))
			ans+=n-2;
	cout<<ans<<'\n';
}

signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);

	int T=1;
	//cin>>T;
	while(T--)
		solve();

	return 0;
}