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

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