#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
ll n;
ll a, b, r;
ll x, y;
ll r2;
vector<ll>v;
vector<ll>w;
ll ans=0;
int main()
{
    ios_base::sync_with_stdio(false);
    cin>>n>>r>>a>>b;
    r2=r*r;
    r2*=a*a+b*b;
    for (int i=1; i<=n; ++i)
    {
        cin>>x>>y;
        ll p=a*x+b*y;
        ll d=b*x-a*y;
        if (r2-d*d>=0)
        {
          ld sq=sqrt(r2-d*d);
          sq*=10000013;
          ll isq=(sq+0.5);
          ll st=sq*p-isq;
          ll en=sq*p+isq;
          v.push_back(st);
          w.push_back(en);
        }
    }
    ll i=0;
    ll j=0;
    while(i<v.size() && j<w.size())
    {
        if (v[i]<=w[j])
        {
            ++i;
            ans=max(ans, i-j);
        }
        else{
            ++j;
        }
    }
    cout<<ans;
}