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 bits = [| yield 1; for i in 1..N -> bitcount i |]
    let cash = new BitArray(N)
    let rec s p = seq {
        let np = p + bits.[p]
        if np = N then yield np
        elif N < np then
            let nm = p - bits.[p]
            if 1 <= nm && not(cash.[nm]) then
                cash.[nm] <- true
                yield nm
                yield! s nm
            else
                failwith "-1"
        else
            cash.[np] <- true
            yield np
            yield! s np
        }
    try
        s 0 |> Seq.length
    with
    | _ -> -1
    |> printfn "%d"
``No.3 ビットすごろく`` ()