#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;

int MyBinarySearch(vector<int> vec, int target)
{
	auto it = vec.begin();
	int sum = 0;
	while (true)
	{
		if (binary_search(it, vec.end(), target))
		{
			sum++;
			it = find(it, vec.end(), target)+1;
		}
		else
		{
			break;
		}
	}
	return sum;
}

int main()
{
	int n;
	long x;
	vector<int> data;
	cin >> n >> x;
	for (int i = 0; i < n; i++)
	{
		int buff;
		cin >> buff;
		data.push_back(buff);
	}
	sort(data.begin(), data.end());
	int sum = 0;
	for (int i = 0; i < data.size(); i++)
	{
		int target = x - data[i];
		sum += MyBinarySearch(data, target);
	}
	cout << sum;

	return 0;
}