#include <iostream>
using namespace std;
void quick_sort(int* a, int l, int r)
{
	int pe;
	int l_hold = l;
	int r_hold = r;
	pe = a[l];
	while (l < r)
	{
		while ((a[r] >= pe) && (l < r))
			r--;
		if (l != r)
		{
			a[l] = a[r];
			l++;
		}
		while ((a[l] <= pe) && (l < r))
			l++;
		if (l != r)
		{
			a[r] = a[l];
			r--;
		}
	}
	a[l] = pe;
	pe = l;
	l = l_hold;
	r = r_hold;
	if (l < pe)
		quick_sort(a, l, pe - 1);
	if (r > pe)
		quick_sort(a, pe + 1, r);
}
int main()
{
	int n;
	cout << "Enter n:";
	cin >> n;
	int t;
	cout << "Enter t:";
	cin >> t;

	int* a = new int[n];
	for (int i = 0; i < n; i++)
		cin >> a[i];

	quick_sort(a, 0, n - 1 );


	int i = 0;
	int j = n - 1;
	int res = 0;

	while (i < j)
	{
		if (a[i] + a[j] > t)
			j--;
		if (a[i] + a[j] < t)
			i++;
		else
		{
			res++;
			i++;
			j--;
		}

	}
	cout << res;


}