#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define fi first
#define se second
#define pll pair<ll, ll>
#define INF (1ll << 60)
#define ppl pair<pll, pll>
#define vl vector<ll>
#define vvl vector<vl>
#define FOR(i,a,b) for(ll i=a;i<b;++i)
#define pb push_back
#define ALL(X) X.begin(),X.end()
#define endl (char)10
using namespace std;

ld dist(ld x, ld y){
    return sqrtl(x*x+y*y);
}

int main() {
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);

    int n;
    cin>>n;

    ld R,A,B;
    cin>>R>>A>>B;

    R+= 1.0e-3;
    vector<pair<ll,ll>> segs;

    for(int i=0;i<n;i++){
        ld xp,yp;
        cin>>xp>>yp;

        // cout << xp << " "<< yp << endl;

        if(A!=0){
            ld a = 1.0l + (B/A)*(B/A);
            ld b = -2.0*xp - 2.0*(B/A)*yp;
            ld c = xp*xp + yp*yp - R*R;

            ld delta = b*b - 4.0*a*c;
            // cout << delta;

            if(delta>=0){
                ld left = (-b-sqrtl(delta))/(2.0*a);
                ld right = (-b+sqrtl(delta))/(2.0*a);
                // cout <<"xs: " <<  left << " " << right<<endl;
            
                left = dist(left , B*left/A);
                right = dist(right , B*right/A);

                if(left > right){
                    swap(left , right);
                }

                segs.push_back({left , 0});
                segs.push_back({right , 1});
            }else{
                // cout << "NOT";
                continue;
            }
        }else{
                ld left = yp + sqrtl(R*R - xp*xp);
                ld right = yp - sqrtl(R*R + xp*xp);

                left = abs(left);
                right = abs(right);

                if(left > right){
                    swap(left , right);
                }

                segs.push_back({left , 0});
                segs.push_back({right , 1});
        }
        // cout << endl;

    }

    sort(segs.begin() , segs.end());

    int open=0;
    int res=0;

    for(auto s : segs){
        // cout << s.first << " , " << s.second << endl;
        if(s.second==0){
            open++;
            res=  max(open, res);
        }else{
            open--;
        }
    }

    cout << res<<endl;
    return 0;
}