#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

int n,r;
int a[2001][2],i,j,k,l;
int most;
double fuck;
int you;

int main()
{
	ifstream fin("fight.in");
	ofstream fout("fight.out");
	
	fin>>n>>r;
	
	most=0;
	
	for (i=1;i<=n;i++)
		fin>>a[i][0]>>a[i][1];
	
	for (i=1;i<=n;i++)
	{
		you=0;
		for (j=1;j<=n;j++)
		{
			fuck=sqrt(pow(((double)a[i][0]-a[j][0]),2)+pow(((double)a[j][1]-a[i][1]),2));
			if (fuck<=r)
				you++;
		}
		if (you>most)
			most=you;
	}
	
	fout<<most;
	
	fin.close();
	fout.close();
	
	return 0;
}