#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int gcd(int a, int b){
    return b?gcd(b, a%b):a;
}

int main(){
    int P, Q;
    while(cin >> P >> Q){
        int N, ans = 0;
        cin >> N;
        vi x(N), y(N);
        rep(i, N)
            scanf("%d%d", &x[i], &y[i]);
        if(P == 0 && Q == 0){
            rep(i, N)if(x[i] == 0 && y[i] == 0)++ans;
        } else{
            int g = gcd(P, Q), p = P / g, q = Q / g;
            rep(i, N)if(x[i] % g == 0 && y[i] % g == 0){
                x[i] /= g;
                y[i] /= g;
                if(((x[i] + y[i]) % 2 && (p + q) % 2) || (x[i] + y[i]) % 2 == 0)
                    ++ans;
            }
        }
        cout << ans << endl;
    }
}