#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-5;
vector <pair <ld , int> > tab;
ll R, A, B;
ll dotpro (pair <ll, ll> a, pair <ll, ll> b)
{
	return a.fi * b.fi + a.se*b.se;
}



int main ()
{
	int n;
	scanf ("%d %lld %lld %lld", &n, &R, &A, &B);
	
	vector <pair <ll, ll> > pkt(n);
	for (auto &p: pkt) scanf ("%lld %lld", &p.fi, &p.se);
	
	pair <ll, ll> AB = mp(A, B);
	
	
	for (auto p: pkt)
	{
		ll d2 = (A*p.se - B*p.fi) * (A*p.se - B*p.fi);
		
		if (d2 > R*R*(A*A+B*B)) continue; //za daleko
		 
		ld rzut = ld(dotpro(p, AB))/ld(A*A+B*B);
		
		ld h = sqrt( ld(R*R) - ld(d2)/ld(A*A+B*B) + eps);
		
		tab.pb(mp(rzut - h, 1));
		tab.pb(mp(rzut + 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);
}