#include <iostream>

using namespace std;

int main() { 
	int n, x, y, r;
	int a, b, count = 0;
	cin >> n >> x >> y >> r;
	while(n--) { 
		cin >> a >> b;
		if ( (a-x)*(a-x) + (b-y)*(b-y) <= r * r )
			count++;
	}
	cout << count;
}