import java.net.NetworkInterface;
import java.util.*;

public class Main {public static int upper_bound(long[] arr, long key) {
	int len = arr.length;
	int lo = 0;
	int hi = len-1;
	int mid = (lo + hi)/2;
	while (true) {
		long cmp = arr[mid]-key;
		if (cmp == 0 || cmp < 0) {
			lo = mid+1;
			if (hi < lo)
				return mid<len-1?mid+1:-1;
		} else {
			hi = mid-1;
			if (hi < lo)
				return mid;
		}
		mid = (lo + hi)/2;
	}
}
	static long gcd(long a,long b){
		return b == 0 ? a : gcd(b, a%b);
	}
	static long lcm(long a, long b){
		return a*b/gcd(a, b);
	}
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		long p = sc.nextLong();
		long q = sc.nextLong();
		int n = sc.nextInt();
		int[] x = new int[n];
		int[] y = new int[n];
		for(int i=0;i<n;i++){
			x[i] = sc.nextInt();
			y[i] = sc.nextInt();
		}
		if(gcd(p, q)==1){
			System.out.println(n);
		}else if(p==0){
			int ans = 0;
			for(int i=0;i<n;i++){
				if( y[i]%q==0 || x[i]%q==0) ans++;
			}
			System.out.println(ans);
		}else if(q==0){
			int ans = 0;
			for(int i=0;i<n;i++){
				if( y[i]%p==0 || x[i]%p==0) ans++;
			}
			System.out.println(ans);
		}else{
			int ans =0;
			for(int i=0;i<n;i++){
				if( (x[i]%p==0 && y[i]%q==0) || (x[i]%q==0 && y[i]%p==0)) ans++;
			}
			System.out.println(ans);
		}
	} 
}