#include <stdio.h>

int p, q, n, x[100000], y[100000];

int gcd(int a, int b) {
	if(b == 0) { return a; }
	return gcd(b, a % b);
}

int main(void) {
	scanf("%d%d%d", &p, &q, &n);
	int i;
	for(i = 0; i < n; i++) {
		scanf("%d%d", &x[i], &y[i]);
	}
	
	int d = gcd(p, q), counter = 0;
	for(i = 0; i < n; i++) {
		if(p != 0 && q != 0) {
			if( x[i] % d == 0 && y[i] % d == 0 &&
				(
					( (p / d) % 2 == 0 || (q / d) % 2 == 0 ) ||
					(x[i] / d + y[i] / d) % 2 == 0
				)
			) { counter++; }
		} else if(p == 0 && q != 0) {
			if( x[i] % q == 0 && y[i] % q == 0 ) { counter++; }
		} else if(p != 0 && q == 0) {
			if( x[i] % p == 0 && y[i] % p == 0 ) { counter++; }
		} else {
			if( x[i] == 0 && y[i] == 0 ) { counter++; }
		}
	}
	
	printf("%d\n", counter);
	
	return 0;
}