import math


def read_data():
    P, Q = map(int, input().split())
    N = int(input())
    xys = []
    for n in range(N):
        x, y = map(int, input().split())
        xys.append((x, y))
    return P, Q, N, xys


def solve(P, Q, N, xys):
    if P == 0 and Q == 0:
        return sum(1 for x, y in xys if x == 0 and y == 0)
    if P == 0 or Q == 0:
        GCD = P + Q
        odd_cycle = True
    else:
        GCD = math.gcd(P, Q)
        LCM = P * Q // GCD
        odd_cycle = (LCM // P + LCM // Q) % 2
    count = 0
    for x, y in xys:
        mx, rx = divmod(x, GCD)
        my, ry = divmod(y, GCD)
        if rx == 0 and ry == 0:
            if odd_cycle or ((mx + my) % 2 == 0):
                count += 1
    return count


P, Q, N, xys = read_data()
print(solve(P, Q, N, xys))