type ABC(stream:System.IO.TextReader) =
  member this.Scan1 f = stream.ReadLine() |> f
  member this.Scan2 f = stream.ReadLine().Split() |> Array.map f |> (fun a -> (a.[0], a.[1]))
  member this.Scan3 f = stream.ReadLine().Split() |> Array.map f |> (fun a -> (a.[0], a.[1], a.[2]))
  member this.Scan4 f = stream.ReadLine().Split() |> Array.map f |> (fun a -> (a.[0], a.[1], a.[2], a.[3]))
  member this.ScanVecH f = stream.ReadLine().Split() |> Array.map f
  member this.ScanVecV n f = [| for i in 1..n -> stream.ReadLine() |> f |]
  member this.ScanMatrix n f  = [ for i in 1..n do yield stream.ReadLine().Split() |> Array.map f ]
  member this.ScanCharMatrix n = [| for i in 1..n -> stream.ReadLine().ToCharArray() |]
  member this.Close () = stream.Close()

let util = ABC(stdin)
  
let N = util.Scan1 int

let cl n =
  match n%2 with
  | 0 -> n/2
  | _ -> 3*n+1 

let rec rfn i x xs =
  let c = cl x
  if List.contains c xs
    then i+1
    else rfn (i+1) (cl x) (c::xs)

rfn 1 N [N]
|> printfn "%d"

util.Close()
