#!/usr/bin/env python3
import math
p, q = map(int,input().split())
n = int(input())
if p == 0 and q == 0:
    zero = True
elif p == 0 and q == 0:
    gcd = p + q
    even = True
    zero = False
else:
    gcd = math.gcd(p, q)
    even = (p / gcd) % 2 == 0 or (q / gcd) % 2 == 0
    zero = False
ans = 0
for i in range(n):
    x, y = map(int,input().split())
    if zero:
        if x == 0 and y == 0:
            ans += 1
    else:
        if x % gcd == 0 and y % gcd == 0:
            if even:
                ans += 1
            else:
                if ((x / gcd) + (y / gcd)) % 2 == 0:
                    ans += 1
print(ans)