from math import gcd

p, q = map(int, input().split())
g = gcd(p, q)
p //= g
q //= g
if (p + q) % 2 == 0:
    bi = True
else:
    bi = False
n = int(input())
ans = 0
for _ in range(n):
    x, y = map(int, input().split())
    if x % g != 0 or y % g != 0:
        continue
    x //= g
    y //= g
    if not bi or (x + y) % 2 == 0:
        ans += 1
print(ans)