from math import gcd
P,Q=map(int, input().split())
if P>Q: P,Q=Q,P
g=gcd(P,Q)
N=int(input())
cnt=0
if P!=0 and Q!=0:
    P//=g
    Q//=g
    for _ in range(N):
        x,y=map(int, input().split())
        if x%g==0 and y%g==0:
            x//=g
            y//=g
            if (x+y)%2==0 or P*Q%2==0:
                cnt+=1
elif P==0 and Q!=0:
    for _ in range(N):
        x,y=map(int, input().split())
        if x%Q==0 and y%Q==0:
            cnt+=1
else:
    for _ in range(N):
        x,y=map(int, input().split())
        if x==0 and y==0:
            cnt+=1
print(cnt)