#include <iostream>
#include <cmath>

using namespace std;

int x, y, n, yb, xb, nr, i;
double d, r;

double Dist(double x1, double y1, double x2, double y2)
{
    return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
}

int main()
{
    cin>>n>>xb>>yb>>r;
    for (i=1; i<=n; i++)
    {
        cin>>x>>y;
        d=Dist(xb, yb, x, y);
        if (d<=r)
            nr++;
    }
    cout<<nr;
    return 0;
}