#include <bits/stdc++.h>
#define rep(i,a,b) for (int i=a; i<b; i++)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(x) (x).begin(),(x).end()
#define debug //
using namespace std;
typedef pair <int, int> PII;
typedef vector <int> VI;
typedef long long ll;
typedef long double ld;

const ld eps = 1e-4;
vector <pair <ld , int> > tab;
ld R, A, B;
ld crosspro (pair <ld, ld> a, pair <ld, ld> b)
{
	return a.fi * b.fi + a.se*b.se;
}



int main ()
{
	int n;
	scanf ("%d %Lf %Lf %Lf", &n, &R, &A, &B);
	
	R+=eps;
	
	vector <pair <ld, ld> > pkt(n);
	for (auto &p: pkt) scanf ("%Lf %Lf", &p.fi, &p.se);
	
	pair <ld, ld> AB = mp(A, B), dal = mp(A * 1e10, B * 1e10);
	
	
	for (auto p: pkt)
	{
		ld d2 = ld((A*p.se - B*p.fi) * (A*p.se - B*p.fi)) / ld(A*A+B*B);
		
		if (d2 + 1e-12 > ld(R*R) ) continue;
		ld h = sqrt( ld(R*R) - d2);	
		
		pair <ld, ld> c = AB, c1, c2;
		c.fi *= crosspro(p, AB) / crosspro(AB,AB);
		c.se *= crosspro(p, AB) / crosspro(AB, AB);
		
		
		pair <ld, ld >moj = mp(dal.fi - c.fi, dal.se - c.se);
		ld dist = sqrt(crosspro(moj, moj));
		
		tab.pb(mp(dist-h, 1));
		tab.pb(mp(dist+h, -1));
	}
	sort(tab.begin(), tab.end());
	int stan = 0, res = 0;
	for (auto p: tab)
	{
		stan+=p.se;
		res = max(res, stan);
	}
	printf ("%d\n", res);
}