#include <bits/stdc++.h>

using namespace std;


typedef long long ll;

#define rep(i, n) for (int i = 0; i < (n); i++)

pair<bool, pair<double, double>> from_pt(int p, int q, int A, int B, int r) {
	double ba = (1.0) * B / A;
	double qa = ba * ba + 1;
	double qb = - (2 * p + 2 * ba * q);
	double qc = p * p + q * q - r*r;

	double discr = qb * qb - 4 * qa * qc;

	if (discr < 0) {
		return {false, {0, 0}};
	}
	else{
		double a = -qb / (2 * qa);
		double b = 1 / (2 * qa);
		double s = discr;
		double x0 = a - b * sqrt(s) - 0.000001;
		double x1 = a + b * sqrt(s) + 0.000001;

		return {true, {x0, x1}};
	}

}

int main(void){
	ios_base::sync_with_stdio(false);
	int n, r, a, b; cin >> n >> r >> a >> b; 
	vector<pair<int,int>> pts;
	vector<pair<double, bool>> edges;
	bool swap = false;
	if (a == 0) {
		swap = true;
		a = b;
		b = 0;
	}

	rep(i, n) {
	   int x, y;
	   cin >> x >> y;
	   if (swap) {
		   int backup = x;
		   x = y;
		   y = backup;
	   }
		auto res = from_pt(x, y, a, b, r);
		if (res.first) {
			auto xs = res.second;
			edges.push_back({xs.first, true});
			edges.push_back({xs.second, false});
		}
	}
	sort(edges.begin(), edges.end());
	int maxcount = 0;
	int curcount = 0;
	rep(i, edges.size()) {
		auto e = edges[i];
		if (e.second) {
			curcount += 1;
			maxcount = max(maxcount, curcount);
		}
		else
		{
			curcount -= 1;
		}
	}
	cout << maxcount << endl;
	
	return 0;
}