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

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;

#define fi first
#define se second
#define repl(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define rep(i,n) repl(i,0,n)
#define each(itr,v) for(auto itr:v)
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define dbg(x) cout<<#x"="<<x<<endl
#define mmax(x,y) (x>y?x:y)
#define mmin(x,y) (x<y?x:y)
#define maxch(x,y) x=mmax(x,y)
#define minch(x,y) x=mmin(x,y)
#define uni(x) x.erase(unique(all(x)),x.end())
#define exist(x,y) (find(all(x),y)!=x.end())
#define bcnt __builtin_popcount

#define INF INT_MAX/3

ll p,q;
ll n;
ll x[101010],y[101010];

int main(){
	cin.sync_with_stdio(false);
  cin>>p>>q>>n;
  rep(i,n){
    cin>>x[i]>>y[i];
  }
  if(p==0&&q==0){
    ll res=0;
    rep(i,n)if(x[i]==0&&y[i]==0)res++;
    cout<<res<<endl;
    return 0;
  }else if(p==0||q==0){
    ll r;
    if(p==0)r=q;
    else r=p;
    ll res=0;
    rep(i,n){
      if(x[i]%r==0&&y[i]%r==0)res++;
    }
    cout<<res<<endl;
    return 0;
  }
  ll res=0;
  ll g=__gcd(p,q);
  p/=g; q/=g;
  rep(i,n){
    if(x[i]%g==0&&y[i]%g==0&&(p%2!=q%2||(p%2==q%2&&(x[i]/g+y[i]/g)%2==0)))res++;
  }
  cout<<res<<endl;
	return 0;
}