{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE BangPatterns #-}

import Control.Applicative
import Control.Monad
import Control.Arrow
import Data.List
import Data.Maybe
import Data.Char
import qualified Data.ByteString.Char8 as B
import Text.Printf

readInt = ( readLn :: IO Int )
readInts = map ( read :: String -> Int ) . words <$> getLine

getList = map ( fst . fromJust . B.readInt ) . B.words <$> B.getLine

which a b f = if f then a else b
mp [ a, b ] = ( a, b )

d = 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991

main = do
	n :: Integer <- readLn
	let
		dd = d * n
		s1 = show d
		s2 = show dd
		l1 = length s1
		l2 = length s2
		k = l2 - l1
	if k == 0
		then printf "0.%s\n" $ s2
		else printf "%s.%s\n" ( take k s2 ) ( drop k s2 )