#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };

ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;

ll gcd(ll a, ll b) {
	if (b == 0) return abs(a);
	else return gcd(b, a % b);
}

bool f(int x, int y, int d) {
	if (!x && !y) return true;
	if (!d) return false;
	return x % d == 0 && y % d == 0;
}

int main() {
	int P, Q; cin >> P >> Q;
	int d = gcd(P * 2, Q * 2);
	int a[] = {0, P, Q, P + Q};
	int b[] = {0, Q, P, P + Q};
	int N; cin >> N;
	int cnt = 0;
	while (N--) {
		int X, Y; cin >> X >> Y;
		bool ok = false;
		for (int i = 0; i < 4; i++)
			if (f(X + a[i], Y + b[i], d))
					ok = true;
		if (ok) cnt++;
	}
	cout << cnt << endl;
}