p,q = map(int,input().split())
N = int(input())

def gcd(a,b):
    if b == 0:return a
    while True:
        r =a % b
        a = b
        b = r
        if r == 0:return a
ans = 0
d = gcd(p,q)
for _ in range(N):
    x,y = map(int,input().split())
    if x % d == 0 and y % d == 0:
        ans += 1
print(ans)