#include <iostream>
using namespace std;

int main(){
	int xa,ya,xb,yb;
	cin >> xa >> ya >> xb >> yb;
	
	int n;
	cin >> n;
	
	int ans =0;
	for(int i=0;i < n;i++){
		int x,y;
		cin >> x >>y;
		
		if((xa-xb)*(y-ya)==(ya-yb)*(x-xa))
			ans++;
	}
	cout << ans;
	return 0;
}
		

三点共线公式：(xb​−xa​)(y−ya​)=(yb​−ya​)(x−xa​)