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

const int MAXN = 100000;
long long A[ MAXN + 1 ];

int main()
{
int i;
int a;
int N;
int X;
int H;
long long iCnt;

	ios::sync_with_stdio( false );
	cin.tie( 0 );

	cin >> N;
	cin >> X;

	if( X > MAXN * 2 )
	{
		cout << 0 << endl;

		return 0;
	}

	for( i = 0; i < N; i++ )
	{
		cin >> a;
		if( a > X ) continue;

		A[ a ]++;
	}

	H = X / 2;
	iCnt = 0;
	for( i = 0; i <= H; i++ )
	{
		iCnt += 2 * A[ i ] * A[ X - i ];
	}

	if( 2 * H == X ) iCnt -= A[ H ] * A[ H ];

	cout << iCnt << endl;

	return 0;
}