#include <iostream>

using namespace std;

int main()
{
    int N,x,y,R,i,nr=0,a,b;
    cin>>N>>x>>y>>R;
    for(i=1;i<=N;i++)
    {
        cin>>a>>b;
        if(a<=x+R && b<=y+R)
            nr++;
    }
    cout<<nr;
    return 0;
}