#include "bits/stdc++.h" using namespace std; #ifdef _DEBUG #include "dump.hpp" #else #define dump(...) #endif #define int long long #define rep(i,a,b) for(int i=(a);i<(b);i++) #define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--) #define all(c) begin(c),end(c) const int INF = sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f; const int MOD = 1'000'000'007; template bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; } template bool chmin(T &a, const T &b) { if (b < a) { a = b; return true; } return false; } int gcd(int x, int y) { return y ? gcd(y, x % y) : x; } int lcm(int x, int y) { return x / gcd(x, y) * y; } int gcd(const vector &v) { int ret = v[0]; for (int i = 1; i < v.size(); i++) ret = gcd(ret, v[i]); return ret; } int lcm(const vector &v) { int ret = v[0]; for (int i = 1; i < v.size(); i++) ret = lcm(ret, v[i]); return ret; } signed main() { cin.tie(0); ios::sync_with_stdio(false); int P, Q; cin >> P >> Q; if (P > Q)swap(P, Q); int N; cin >> N; vector X(N), Y(N); rep(i, 0, N) { cin >> X[i] >> Y[i]; } int ans = 0; if (P == 0 && Q == 0) { rep(i, 0, N) { if (X[i] == 0 && Y[i] == 0) { ans++; } } } else if (P == 0) { rep(i, 0, N) { if (X[i] % Q == 0 && Y[i] % Q == 0) { ans++; } } } else { int g = gcd(P, Q); P /= g; Q /= g; rep(i, 0, N) { if (X[i] % g || Y[i] % g)continue; if (P % 2 && Q % 2) { if ((X[i] + Y[i]) % 2)continue; ans++; } else { ans++; } } } cout << ans << endl; return 0; }