import sys

sys.setrecursionlimit(10 ** 6)
from bisect import *
from collections import *
from heapq import *

def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def SI(): return sys.stdin.readline()[:-1]
def LLI(rows_number): return [LI() for _ in range(rows_number)]
int1 = lambda x: int(x) - 1
def MI1(): return map(int1, sys.stdin.readline().split())
def LI1(): return list(map(int1, sys.stdin.readline().split()))
p2D = lambda x: print(*x, sep="\n")
dij = [(0, 1), (1, 0), (0, -1), (-1, 0)]

def gcd(a, b):
    if a * b == 0: return a + b
    while b: a, b = b, a % b
    return a

def main():
    p, q = MI()
    n = II()
    g = gcd(p, q)
    ans = 0
    if g==0:
        for _ in range(n):
            x, y = MI()
            if (x,y)==(0,0):ans+=1
        print(ans)
        exit()
    p, q = p // g, q // g
    odd = q & 1 and p & 1
    if odd:
        for _ in range(n):
            x, y = MI()
            x, y = abs(x), abs(y)
            if x % g == 0 and y % g == 0 and (x // g + y // g) & 1 == 0: ans += 1
    else:
        for _ in range(n):
            x, y = MI()
            x, y = abs(x), abs(y)
            if x % g == 0 and y % g == 0: ans += 1

    print(ans)

main()