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

using namespace std;

typedef long double ld;

constexpr long double eps = 1e-11L;

int sgn(ld x) { return (x > 0) - (x < 0); }
struct Point {
	typedef Point P;

	ld x, y;
	Point(ld x=0, ld y=0): x(x), y(y) {}
	
	bool operator == (const P& p) const { return abs(x - p.x) < eps && abs(y - p.y) < eps; }
	
	P operator - (const P& p) const { return {x - p.x, y - p.y}; }
	P operator * (ld d) const { return {x * d, y * d}; }
	P operator / (ld d) const { return {x / d, y / d}; }
	
	ld dot(const P& p) const { return x * p.x + y * p.y; }
	ld cross(const P& p) const { return x * p.y - y * p.x; }
	ld dist2() const { return x * x + y * y; }
	ld dist() const { return sqrt(dist2()); }

	P unit() const { return *this / dist(); }
	P perp() const { return {-y, x}; }
	P normal() const { return perp().unit(); }
} O(0, 0);

ld lineDist(const Point& l, const Point& p) {
	return l.cross(p) / l.dist();
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int n;
	ld r;
	Point line;
	vector<pair<ld, int>> events;
	
	cin>>n>>r>>line.x>>line.y;
	
	for (int i = 0; i < n; ++i) {
		Point p;
		cin>>p.x>>p.y;
		
		ld d = lineDist(line, p);
		Point project = p - line.normal() * d;
		ld c = project.dist();
		d = abs(d);
		
		if (project.y < -eps || (abs(project.y) < eps && project.x < -eps))
			c = -c;
		
		if (d > r + eps) continue;
		ld w = sqrt(r * r - d * d + eps);
		
		events.emplace_back(c - w - eps, 1);
		events.emplace_back(c + w + eps, -1);
		//cout<<d<<' '<<c - w<<' '<<c + w<<endl;
	}
	
	sort(events.begin(), events.end());
	int x = 0, sol = 0;
	for (const auto& e: events) {
		x += e.second;
		sol = max(sol, x);
	}
	cout<<sol<<endl;
}