let D'  = 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991I
let len = D' |> string |> fun x -> x.ToCharArray() |> Array.length
let N   = stdin.ReadLine() |> int |> bigint

D' * N |> string |> fun x -> x.ToCharArray()
|> function 
    | str when (str |> Array.length) = len ->
        "0." + new string(str)
    | str ->
        let overSize = (str |> Array.length) - len
        let f = str.[0        .. (overSize-1)]
        let b = str.[overSize ..             ]
        new string(f) + "." + new string(b)
    |> printfn "%s"