open System.Collections
let ``No.3 ビットすごろく`` () =
    let bitcount (bit:int) =
        let a = (bit &&& 0x55555555) + (bit >>> 1 &&& 0x55555555) in
        let b = (a &&& 0x33333333) + (a >>> 2 &&& 0x33333333) in
        let c = (b &&& 0x0F0F0F0F) + (b >>> 4 &&& 0x0F0F0F0F) in
        let d = (c &&& 0x00FF00FF) + (c >>> 8 &&& 0x00FF00FF) in
        (d &&& 0x0000FFFF) + (d >>> 16 &&& 0x0000FFFF)
    let N = int <| stdin.ReadLine()
    let aa = [| yield 0; yield 1; for i in 2..N -> -1 |]
    let f2 f p p2 l =
        if f p2 && aa.[p2] = -1 then
            aa.[p2] <- aa.[p] + 1
            l@[p2]
        else l
    let rec f = function
        | p::ps ->
            if p = N then aa.[N]
            else
                let bc = bitcount p
                let ps = f2 ((<=)1) p (p-bc) ps
                let ps = f2 ((>=)N) p (p+bc) ps
                f ps
        | _ -> -1
    printfn "%d" <| f [1]
``No.3 ビットすごろく`` ()