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

std::vector<std::pair<long double,int> > v;

long long x,y;
long long r;

void insert(long long px, long long py)
{
	long double a = x*x+y*y;
	long double b = -2*x*px-2*y*py;
	long double c = px*px+py*py-r*r;
	long double dis = b*b-4*a*c;
	if(dis < 0) return;
	long double a1 = ((-b)+std::sqrt((dis)))/(2*a);
	long double a2 = ((-b)-std::sqrt((dis)))/(2*a);
	//std::cout << "for " << px << " " << py << " inserting:" << a1 << " " << a2 << std::endl;
	v.push_back({a1+0.0000000000001,1});
	v.push_back({a2-0.0000000000001,-1});
}

int main()
{
	int n;
	std::cin >> n >> r >> x >> y;
	while(n--)
	{
		int tmpa,tmpb;
		std::cin >> tmpa >> tmpb;
		insert(tmpa,tmpb);
	}
	std::sort(v.begin(),v.end());
	int max = 0;
	int sum = 0;
	for(int i=0;i<v.size();i++)
	{
	//	std::cout << v[i].first << " " << v[i].second << std::endl;
		sum -= v[i].second;
		if(sum > max) max = sum;
	}
	std::cout << max << std::endl;
}