#include <iostream>
using namespace std;
void qs_helper(int* A, int l, int r)
{
	if (r > l)
	{
		int i = 0, j, k, pe;
		int m = (l + r) / 2;
		if (A[l] < A[m])
			if (A[m] < A[r])
				swap(A[l], A[m]);
			else
				if (A[l] < A[r])
					swap(A[l], A[r]);
				else
					if (A[r] < A[m])
						swap(A[l], A[m]);
					else
						if (A[r] < A[l])
							swap(A[l], A[r]);
		pe = A[i]; i = l; j = l + 1; k = r;
		while (j <= k)
			if (A[j] == pe)
				j++;
			else
				if (A[j] < pe)
				{
					swap(A[i], A[j]);
					i++; j++;
				}
				else
				{
					swap(A[j], A[k]);
					k--;
				}



	}


}
void quick_sort(int* A, int n)
{
	qs_helper(A, 0, n - 1);
}
int main()
{
	int n;
	cin >> n;
	int t;
	cin >> t;

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


}