import math

P,Q = list(map(int, input().split()))
N = int(input())

g = math.gcd(P,Q)

if g != 0:
    P = P // g
    Q = Q // g

count = 0    
for _ in range(N):
    x,y = list(map(int, input().split()))
    
    if g == 0:
        if x == 0 and y == 0:
            count = count + 1
        continue
        
    if x % g != 0 or y % g != 0:
        continue

    x = x // g
    y = y // g
    if (P+Q) % 2 == 0 and (x+y) % 2 != 0:
        continue

    count = count + 1

print(count)