import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
def norm(a):
    return a[0]*a[0]+a[1]*a[1]

def round(a, b):
    return (a*2+b)//(2*b)

def div(a, b):
    c = (round(a[0]*b[0] + a[1]*b[1], norm(b)), round(a[1]*b[0]-a[0]*b[1], norm(b)))
    return a[0] - b[0]*c[0] + b[1]*c[1], a[1] - b[0]*c[1] - b[1]*c[0]

def gcd(a, b):
    if b == (0,0):
        return a
    return gcd(b, div(a, b))


p, q = na()
if p == 0 and q == 0:
    n = ni()
    ans = 0
    for i in range(n):
        x, y = na()
        if x == 0 and y == 0:
            ans += 1
    print(ans)
    exit()

r = gcd((p, q), (p, -q))
n = ni()
ans = 0
for _ in range(n):
    x, y = na()
    if (r[0] * x + r[1] * y) % norm(r) == 0 and (r[0] * y - r[1] * x) % norm(r) == 0:
        ans += 1
print(ans)