#include <bits/stdc++.h>

using namespace std;

int main(){
	int p,q,d,f,n,x,y,s=0;
	scanf("%d%d%d",&p,&q,&n);
	if(p==0&&q==0){
		while(n--){
			scanf("%d%d",&x,&y);
			if(x==0&&y==0)s++;
		}
	}else{
		d=gcd(p,q);
		if(p/d%2==0||q/d%2==0)f=1;
		else f=0;
		while(n--){
			scanf("%d%d",&x,&y);
			if(x%d==0&&y%d==0&&(f||(x/d+y/d)%2==0))s++;
		}
	}
	printf("%d\n",s);
	return 0;
}