kaidanStr :: String -> String
kaidanStr str =
    let
        w = words str
        s = read (w !! 0)
        f = read (w !! 1)
    in
        show $ kaidan s f

kaidan :: Int -> Int -> Int
kaidan s f = iter s 1
    where
        iter i j    | i < f     = j
                    | i == f    = j + 1
                    | otherwise = iter (i - f) (j + 1)

main = do
    str <- getLine
    putStrLn $ kaidanStr str