#include "bits/stdc++.h"
#include<unordered_map>
#include<unordered_set>
#pragma warning(disable:4996)
using namespace std;
using ld = long double;
template<class T>
using Table = vector<vector<T>>;

long long int gcd(long long int l, long long int r) {
	if (l > r)return gcd(r, l);
	else {
		if (r%l) {
			return gcd(l, r%l);

		}
		else {
			return l;
		}
	}
}
int main() {
	long long int P, Q; cin >> P >> Q;
	long long int agcd = gcd(P, Q);
	P /= agcd;
	Q /= agcd;
	int N; cin >> N;
	int ans = 0;
	while (N--) {
		long long int X, Y; cin >> X >> Y;
		X = abs(X);
		Y = abs(Y);
		if ((!(X%agcd) && (!(Y%agcd)))) {
			X /= agcd;
			Y /= agcd;
			if (P % 2 && Q % 2) {
				if ((X % 2) ^ (Y % 2)) {

				}
				else {
					ans++;
				}
			}
		}
	}
	cout << ans << endl;
	return 0;
}