import Control.Applicative

width :: Int -> Int -> Int
width a n = minimum (map (\b -> n - (a * b) + abs (a - b)) [1..m])
    where m = div n a

main :: IO ()
main = do
    n <- readLn
    let e = map (\a -> width a n) [1..n]

    putStrLn $ show $ minimum e