import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Iterator;


public class Main_yukicoder321_1 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Printer pr = new Printer(System.out);

        int p = sc.nextInt();
        int q = sc.nextInt();
        if (p < q) {
        	int tmp = p;
        	p = q;
        	q = tmp;
        }

        int n = sc.nextInt();
        int ret = 0;
        for (int i = 0; i < n; i++) {
        	int x = Math.abs(sc.nextInt());
        	int y = Math.abs(sc.nextInt());

        	if (p == 0) {
        		if (x == 0 && y == 0) {
        			ret++;
        		}
        	} else if (q == 0) {
        		if (x % p == 0 && y % p == 0) {
        			ret++;
        		}
        	} else {
        		int tmp;
        		tmp = gcd(p, q);

        		if (p / tmp % 2 == 0 || q / tmp % 2 == 0) {
        			if (x % tmp == 0 && y % tmp == 0) {
        				ret++;
        			}
        		} else {
            		if ((x % (2 * tmp) == 0 && y % (2 * tmp) == 0) || ((x + y) % (2 * tmp) == 0 && (x - y) % (2 * tmp) == 0)) {
            			ret++;
            		}
        		}
        	}
        }

        pr.println(ret);

        pr.close();
        sc.close();
    }

	private static int gcd(int n, int m) {
		if (m == 0) {
			return n;
		} else {
			return gcd(m, n % m);
		}
	}

	@SuppressWarnings("unused")
	private static class Scanner {
		BufferedReader br;
		Iterator<String> it;

		Scanner (InputStream in) {
			br = new BufferedReader(new InputStreamReader(in));
		}

		String next() throws RuntimeException  {
			try {
				if (it == null || !it.hasNext()) {
					it = Arrays.asList(br.readLine().split(" ")).iterator();
				}
				return it.next();
			} catch (IOException e) {
				throw new IllegalStateException();
			}
		}

		int nextInt() throws RuntimeException {
			return Integer.parseInt(next());
		}

		long nextLong() throws RuntimeException {
			return Long.parseLong(next());
		}

		float nextFloat() throws RuntimeException {
			return Float.parseFloat(next());
		}

		double nextDouble() throws RuntimeException {
			return Double.parseDouble(next());
		}

		void close() {
			try {
				br.close();
			} catch (IOException e) {
//				throw new IllegalStateException();
			}
		}
	}

	private static class Printer extends PrintWriter {
		Printer(PrintStream out) {
			super(out);
		}
	}
}