#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int P, Q, N, g, ans = 0;
    cin >> P >> Q >> N;
    g = __gcd(P, Q);
    bool flag = false;
    if(g >= 1){
        flag = (P / g % 2 == Q / g % 2);
    }
    for(int i = 0; i < N; i++){
        int x, y;
        cin >> x >> y;
        if(g == 0){
            ans += (x == 0 && y == 0);
            continue;
        }
        if(x % g == 0 && y % g == 0){
            if(flag){
                x /= g, y /= g;
                ans += (x + y) % 2 == 0;
            }else{
                ans++;
            }
        }
    }
    cout << ans << '\n';
}