#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef complex<double> P;
typedef pair<int,int> pii;
#define REP(i,n) for(ll i=0;i<n;++i)
#define REPR(i,n) for(ll i=1;i<n;++i)
#define FOR(i,a,b) for(ll i=a;i<b;++i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define MOD (ll)(1e9+7)
#define ADD(a,b) a=((a)+(b))%MOD
#define FIX(a) ((a)%MOD+MOD)%MOD

int main(){
  ll p,q;
  ll n;
  cin>>p>>q>>n;
  if(p>q)swap(p,q);
  ll g = __gcd(p,q);
  ll sa;
  if(g!=0)sa = (q-p)/g;
  ll result = 0;
  REP(i,n){
    ll x,y;
    cin >> x >> y;
    x = abs(x);
    y = abs(y);
    if(p==0 && q==0){
      if(x==0 && y==0)++result;
    }else if(p==0){
      if(x%q==0 && y%q==0)++result;
    }else{
      if(x%g!=0 || y%g!=0)continue;
      x/=g; y/=g;
      if(sa%2==1)++result;
      else{
        if((x+y)%2==0)++result;
      }
    }
  }
  cout << result << endl;
  return 0;
}