#include <bits/stdc++.h>
using namespace std;
#define int long long   // <-----!!!!!!!!!!!!!!!!!!!

#define rep(i,n) for (int i=0;i<(n);i++)
#define rep2(i,a,b) for (int i=(a);i<(b);i++)
#define rrep(i,n) for (int i=(n)-1;i>=0;i--)
#define rrep2(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define all(a) (a).begin(),(a).end()

typedef long long ll;
typedef pair<int, int> P;

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

signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    int p, q;
    cin >> p >> q;
    int r = gcd(p, q);
    if (r > 0) {
        p /= r;
        q /= r;
    }
    int n;
    cin >> n;
    int ans = 0;
    rep(i, n) {
        int x, y;
        cin >> x >> y;
        x = abs(x);
        y = abs(y);
        if (p == 0 && q == 0) {
            // p = q = 0なら原点しか行けない
            if (x == 0 && y == 0) {
                ans++;
            }
        } else {
            if (x % r != 0 || y % r != 0) {
                continue;
            }
            x /= r;
            y /= r;
            if (p % 2 != 0 && q % 2 == 0) {
                if ((x + y) % 2 == 0) {
                    ans++;
                }
            } else {
                ans++;
            }
        }
    }

    cout << ans << endl;
}