import Control.Applicative ((<$>))
import Control.Monad (replicateM)

tuplify2 :: [a] -> (a, a)
tuplify2 [x, y] = (x, y)

generateJudge :: Integral a => a -> a -> ((a, a) -> Bool)
generateJudge 0 0 = \(x, y) -> x == 0 && y == 0
generateJudge p q
    | odd s0 = f
    | otherwise = \(x, y) -> f (x, y) && even (div x g + div y g)
    where
        g = gcd p q
        s0 = sum $ map (`div` g) [p, q]
        f (x, y) = mod x g == 0 && mod y g == 0

solve :: Integral a => a -> a -> [(a, a)] -> Int
solve p q = length . filter (generateJudge p q)

main :: IO ()
main = do
    [p, q] <- map read . words <$> getLine
    n <- readLn
    cs <- map (tuplify2 .
        map read . words) <$> replicateM n getLine
    print $ solve p q cs