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

int cnt = 0;
int xa, ya, xb, yb;
void judge(int x, int y){
	double res = 1.0*(ya - yb)*(x - xb)/(xa - xb) + yb;
	if(res == y) cnt ++;
}

int main(){
	

	cin >> xa >> ya >> xb >> yb;
	
	int n; cin >> n;
	while(n --) {
		int x, y; cin >> x >> y;
		judge(x, y);
	}
	
	cout << cnt;
	
	return 0;
}