#include <bits/stdc++.h>
using namespace std;
#define all(c) (c).begin(),(c).end()
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define iter(c) __typeof((c).begin())
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
#define mem(a) memset(a,0,sizeof(a))
#define pd(a) printf("%.10f\n",a)
#define pb(a) push_back(a)
#define in(a) insert(a)
#define pi M_PI
#define R cin>>
#define F first
#define S second
#define C class
#define ll long long
#define ln cout<<'\n'
#define _(_1,_2,_3,N,...)N
#define pr(...) _(__VA_ARGS__,pr3,pr2,pr1)(__VA_ARGS__)
template<C T>void pr1(T a){cout<<a;ln;}
template<C T,C T2>void pr2(T a,T2 b){cout<<a<<' '<<b;ln;}
template<C T,C T2,C T3>void pr3(T a,T2 b,T3 c){cout<<a<<' '<<b<<' '<<c;ln;}
template<C T>void PR(T a,int n){rep(i,n){if(i)cout<<' ';cout<<a[i];}ln;}
bool check(int n,int m,int x,int y){return x>=0&&x<n&&y>=0&&y<m;}
const ll MAX=1000000007,MAXL=1LL<<60;
typedef pair<int,int> P;

void Main() {
  int a,b,n;
  cin >> a >> b >> n;
  if(a>b) swap(a,b);
  int ans=0;
  while(n--) {
    int x,y;
    cin >> x >> y;
    x=abs(x);y=abs(y);
    int z=x+y;
    if(!a) {
      if(!b) {
        if(!x&&!y) ans++;
      } else {
        if(x%b==0&&y%b==0) ans++;
      }
    } else {
      int c=__gcd(a,b);
      if(x%c||y%c) continue;
      if(c==a) {
        if(b/a%2) c*=2;
      } else if(a%2) {
        if((b-a)%2==0) c*=2;
      } else if(a%8==0) {
      } else if(a%4==0) {
        if((b-a)%8==0) c*=2;
      } else {
        if((b-a)%4==0) c*=2;
      }
      if(z%c==0) ans++;
    }
  }
  pr(ans);
}

int main() {
  ios::sync_with_stdio(0);cin.tie(0);
  Main();return 0;
}