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

#define int long long

typedef pair<int,int>pint;
typedef vector<int>vint;
typedef vector<pint>vpint;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
template<class T,class U>void chmin(T &t,U f){if(t>f)t=f;}
template<class T,class U>void chmax(T &t,U f){if(t<f)t=f;}

int P,Q;
int N;

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

signed main(){
    cin>>P>>Q;
    cin>>N;
    int g=gcd(P,Q);
    if(g)P/=g;Q/=g;
    int ans=0;
    rep(i,N){
        int x,y;cin>>x>>y;x=abs(x);y=abs(y);
        if(!P&&!Q){
            if(!x&&!y)ans++;
            continue;
        }
        if(x%g||y%g)continue;
        x/=g;y/=g;
        if(P%2==Q%2){
            if(x%2==y%2)ans++;
        }
        else{
            ans++;
        }
    }
    cout<<ans<<endl;

    return 0;
}