#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]);
	}
	
	if(p < q) { int temp = p; p = q; q = temp; }
	int d = gcd(p, q), counter = 0;
	for(i = 0; i < n; i++) {
		if(q != 0) {
			if(
				x[i] % d == 0 && y[i] % d == 0 &&
				( ((p + q) / d) % 2 == 1 || ((x[i] + y[i]) / d) % 2 == 0 )
			) { counter++; }
		} else if(p != 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;
}