#include<bits/stdc++.h>
using namespace std;

#define double long double

double dist(double a, double b, double c, double d){
		return (a - c)*(a - c) + (b - d)*(b - d);
}

int main(){
	ios::sync_with_stdio (false);
	cin.tie(0);
	int n;
	int aa, bb,rr;
	double a, b, r;
	vector<pair<double, int> > inter;
	
	double x[n], y[n];
	cin >> n >> rr >> aa >> bb;
	a = aa;
	b = bb;
	r = rr;
	r += 5 * 1e-4;
	
	for(int i = 0; i<n; i++){
		int k, l;
		cin >> k >> l;
		x[i] = k;
		y[i] = l;
		if(abs(a) < abs(b)) swap(x[i], y[i]);
	}
	if(abs(a) < abs(b)) swap(a, b);
	
	for(int i = 0; i<n; i++){
		
		double k = (1.0 + b*b/(a*a));
		double l = (-2*x[i]-2*y[i]*b/a);
		double m = x[i]*x[i] + y[i]*y[i] - r*r;
		if(l*l - 4.0*k*m <= 1e-6) continue;
		if (k == 0.0) {while (1);}
		double x0 = (-l + sqrt(l*l - 4.0*k*m)) / (2.0 * k);
		double x1 = (-l - sqrt(l*l - 4.0*k*m)) / (2.0 * k);
		
		inter.push_back({x1, 1});
		inter.push_back({x0, -1});
	}
	//cout << inter.size() << endl;
	sort(inter.begin(), inter.end());
	int cur = 0;
	int ans = 0;
	for(auto x: inter){
		//cout << x.first << " " << x.second << endl;
		cur += x.second;
		ans = max(ans, cur);
	}
	
	cout << ans << endl;
}