--import Control.Applicative ((<$>))
import Control.Monad (replicateM)
import Prelude hiding (lcm)
import Data.Char (isSpace)
import Data.List (transpose, unfoldr)
import qualified Data.ByteString.Char8 as BSC8


getLL :: (BSC8.ByteString -> [Integer]) -> IO [Integer]
getLL f = f <$> BSC8.getLine

readILL :: (BSC8.ByteString -> Maybe (Integer, BSC8.ByteString)) -> (BSC8.ByteString -> [Integer])
readILL f = unfoldr g
    where
        g s = do
            (n, s') <- f s
            return (n, BSC8.dropWhile isSpace s')

main :: IO ()
main = do
    [t, a, b] <- getLL (readILL BSC8.readInteger)
    print $ solve t a b

solve :: Integer -> Integer -> Integer -> Integer
solve t a b = aa + bb - cc
    where
        c = lcm a b
        aa = if t `mod` a == 0 then (t `div` a) else (t `div` a) + 1
        bb = if t `mod` b == 0 then (t `div` b) else (t `div` b) + 1
        cc = if c >= t
                then 1
                else if t `mod` c == 0 then (t `div` c) else (t `div` c) + 1

lcm :: Integer -> Integer -> Integer
lcm a b = a `div` (gcd a b) * b