#include <iostream>
using namespace std;

int main(){
  int Xa,Xb,Ya,Yb;
  cin>>Xa>>Ya>>Xb>>Yb;
  int n;
  cin>>n;
  int x,y;
  int count=0;
  for(int i=0;i<n;i++){
    cin>>x>>y;
    if((Yb-y)*(x-Xa)==(y-Ya)*(Xb-x))count++;
  }
  cout<<count;
  return 0;
}