#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = uint32_t;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    int p, q, n;
    cin >> p >> q >> n;
    int cnt = 0;
    if(p == 0 && q == 0){
        for (int i = 0; i < n; ++i) {
            int x, y;
            scanf("%d %d", &x, &y);
            if(x == 0 && y == 0){
                cnt++;
            }
        }
    }else if(p == 0 || q == 0){
        if(q == 0) swap(p, q);
        for (int i = 0; i < n; ++i) {
            int x, y;
            scanf("%d %d", &x, &y);
            if(x % q == 0 && y % q == 0){
                cnt++;
            }
        }
    }else {
        int g = __gcd(p, q);
        p /= g; q /= g;
        if(p%2 == 0 || q%2 == 0) {
            for (int i = 0; i < n; ++i) {
                int x, y;
                scanf("%d %d", &x, &y);
                if(x % g == 0 && y % g == 0){
                    cnt++;
                }
            }
        }else {
            for (int i = 0; i < n; ++i) {
                int x, y;
                scanf("%d %d", &x, &y);
                if(x % g == 0 && y % g == 0 && (x/g+y/g) % 2 == 0){
                    cnt++;
                }
            }
        }
    }
    cout << cnt << "\n";
    return 0;
}