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

typedef long long ll;
typedef double lf;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;

#define TRACE(x) cerr << #x << ' ' << x << endl
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) FOR(i, 0, n)
#define _ << ' ' <<

#define fi first
#define sec second
#define se second
#define mp make_pair
#define pb push_back

const lf EPS = 1e-12;

inline bool lt(const lf a, const lf b) { return b - a > EPS; }
inline bool eq (const lf a, const lf b) { return !lt(a, b) && !lt(b, a); }
inline bool gt(const lf a, const lf b) { return lt(b, a); }

typedef double T;

struct pt { 
  T x, y;

  pt(){}
  pt (T a, T b) {
    x = a;
    y = b;
  }

  pt operator + (pt p) { return {x+p.x, y+p.y};}
  pt operator - (pt p) { return {x-p.x, y-p.y};}
  pt operator * (T d) { return {x*d, y*d};}
  pt operator / (T d) { return {x/d, y/d};}
};


T sq(pt p) { return p.x * p.x + p.y * p.y;}
lf abs(pt p) { return sqrt(sq(p));}


pt perp(pt p) {return {-p.y, p.x};}

T cross(pt v, pt w) { return v.x*w.y - v.y * w.x;}


struct line {
  pt v; T c;
  line (pt p, pt q) : v(q-p), c(cross(v,p)) {}
  T side(pt p) {return cross(v,p)-c;}
  pt proj(pt p) {return p-perp(v)*side(p)/sq(v);}
};


int n;
T A, B;

bool cmp(pair <lf, int> a, pair <lf, int> b) {
  if (eq(a.fi, b.fi)) return a.sec < b.sec;
  return lt(a.fi, b.fi);
}

T R;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  scanf("%d %lf %lf %lf",&n,&R,&A,&B);
  line L = line(pt(0, 0), pt(A, B));

  vector <pair <lf, int> > v;
  pt P = pt(1e8 * A, 1e8 * B);

  REP(i, n) {
    lf x, y;
    scanf("%lf %lf",&x,&y);
    pt t = pt(x, y);
    pt Y = L.proj(t);
    T d = abs(t - Y);
    if (gt(d, R)) continue;
    lf tt = sqrt(R*R - d*d);
    lf lo = abs(Y - P) - tt;
    lf hi = abs(Y - P) + tt;
    v.pb({lo, -1});
    v.pb({hi, 1});
  }

  sort(v.begin(), v.end(), cmp);

  int tmp = 0;
  int sol = 0;
  REP(i, (int)v.size()) {
    tmp -= v[i].sec;
    sol = max(sol, tmp);
  }

  printf("%d\n",sol);

  return 0;
}