let s = stdin.ReadLine()

let xs =
    "0" + s
    |> Seq.map (string >> int)
    |> Seq.toArray

let len = xs.Length
let arr1 = Array.create len 0
arr1.[len - 1] <- 1
let arr2 = Array.create len 0
let mutable flg = true

let cmp (a: int array) (b: int array) =
    let mutable i = 0
    while i < len && a.[i] = b.[i] do
        i <- i + 1
    if i < len then
        compare a.[i] b.[i]
    else
        0

while flg do
    if cmp xs arr1 = -1 then
        flg <- false
    else
        for i = 0 to len - 1 do
            arr2.[i] <- arr1.[i]
        for i = 1 to len - 1 do
            if arr1.[i] >= 5 then
                arr1.[i - 1] <- arr1.[i - 1] + 1
            arr1.[i] <- arr1.[i] * 2 % 10

arr2
|> Array.skipWhile (fun v -> v = 0)
|> Array.map string
|> String.concat ""
|> printfn "%s"