#include <bits/stdc++.h>
using namespace std;
using i64 = int64_t;
using vi = vector<i64>;
using vvi = vector<vi>;

int main() {
    i64 p, q;
    cin >> p >> q;
    i64 g = __gcd(p, q);
    int cnt = 0;
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        int x, y;
        cin >> x >> y;
        if (x % g == 0 && y % g == 0 && ((p + q) / g % 2 == 1 || ((x + y + p + q) / g) % 2 == 0)) {
            cnt++;
        }
    }
    cout << cnt << endl;
}