#include <bits/stdc++.h>
using namespace std;
int64_t in_div(int64_t n,int64_t m){
  if((n>=0 && m>=0)||(0>=n && 0>=m)){
    n=abs(n);
    m=abs(m);
    return (2*n/m+1)/2;
  }
  else{
    n=abs(n);
    m=abs(m);
    return -(2*n/m+1)/2;
  }
}

pair<int64_t,int64_t> co_mul(pair<int64_t,int64_t> a,pair<int64_t,int64_t> b){
  pair<int64_t,int64_t> ans(a.first*b.first-a.second*b.second,b.first*a.second+a.first*b.second);
  return ans;
}

pair<int64_t,int64_t> co_div(pair<int64_t,int64_t> a,pair<int64_t,int64_t> b){
  int64_t mod=b.first*b.first+b.second*b.second;
  b.second=-b.second;
  pair<int64_t,int64_t> mul(co_mul(a,b).first,co_mul(a,b).second);
  pair<int64_t,int64_t> ans(in_div(mul.first,mod),in_div(mul.second,mod));
  return ans;
}

pair<int64_t,int64_t> co_rem(pair<int64_t,int64_t> a,pair<int64_t,int64_t> b){
  pair<int64_t,int64_t> div(co_div(a,b).first,co_div(a,b).second);
  pair<int64_t,int64_t> ans(a.first-co_mul(b,div).first,a.second-co_mul(b,div).second);
  return ans;
}

pair<int64_t,int64_t> co_GCD(pair<int64_t,int64_t> a,pair<int64_t,int64_t> b){
  if(co_rem(a,b).first==0 && co_rem(a,b).second==0){
    return b;
  }
  return co_GCD(b,co_rem(a,b));
}

int main(){
  int64_t P,Q,N;
  cin>>P>>Q>>N;
  vector<pair<int64_t,int64_t>> kid(N);
  for(int i=0;i<N;i++){
    cin>>kid.at(i).first>>kid.at(i).second;
  }
  pair<int64_t,int64_t> V1(P,Q);
  pair<int64_t,int64_t> V2(P,-Q);
  pair<int64_t,int64_t> zero(0,0);
  int ans=0;
  if(P==0 && Q==0){
    for(int i=0;i<N;i++){
      if(kid.at(i)==zero){
        ans++;
      }
    }
    cout<<ans<<endl;
  }
  else{
    for(int i=0;i<N;i++){
      if(co_rem(kid.at(i),co_GCD(V1,V2))==zero){
        ans++;
      }
    }
    cout<<ans<<endl;
  }
  
}