#include <bits/stdc++.h>

using namespace std;

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI  = acos(-1.0);

int main(){
  cin.tie(0);
  ios_base::sync_with_stdio(false);

  LL P, Q; cin >> P >> Q;
  LL N; cin >> N;
  LL ans = 0;
  if(Q < P) swap(P, Q);
  if(P == 0 && Q == 0){
	REP(i,N){
	  LL x, y; cin >> x >> y;
	  if(x == 0 && y == 0) ++ans;
	}
	cout << ans << endl;
	return 0;
  }
  
  LL d = __gcd(P, Q);
  LL n = Q / d, m = P / d;
  n %= 2; m %= 2;
  LL tmp = n*Q + m*P;
  tmp = __gcd(tmp, 2*P);
  tmp = __gcd(tmp, 2*Q);
  REP(i,N){
	LL x, y; cin >> x >> y;
	x = abs(x); y = abs(y);
	if(x % tmp == 0 && y % tmp == 0)
	  ++ans;
	else if((x+P)%tmp == 0 && (y+Q) % tmp == 0)
	  ++ans;
  }

  cout << ans << endl;
  
  return 0;
}