#include <bits/stdc++.h>
#define GET_MACRO(a, b, c, NAME, ...) NAME
#define rep(...) GET_MACRO(__VA_ARGS__, rep3, rep2)(__VA_ARGS__)
#define rep2(i, a) rep3 (i, 0, a)
#define rep3(i, a, b) for (int i = (a); i < (b); i++)
#define repr(...) GET_MACRO(__VA_ARGS__, repr3, repr2)(__VA_ARGS__)
#define repr2(i, a) repr3 (i, 0, a)
#define repr3(i, a, b) for (int i = (b) - 1; i >= (a); i--)
template<class T1, class T2> inline bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); }
template<class T1, class T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
using namespace std;
typedef long long ll;

int main() {
	ll P, Q;
	int N;
	cin >> P >> Q >> N;
	int ans = 0;
	ll g = __gcd(P, Q);
	if (g != 0) {
		P /= g;
		Q /= g;
	}
	rep (i_, N) {
		ll x, y;
		cin >> x >> y;
		if (P == 0 && Q == 0) {
			ans += x == 0 && y == 0;
			continue;
		}
		if (x % g == 0 && y % g == 0) {
			x /= g; y /= g;
			if (P % 2 == 1 && Q % 2 == 1) {
				if ((x + y) % 2 == 0) {
					ans++;
				}
			} else {
				ans++;
			}
		}
	}
	cout << ans << endl;
	return 0;
}