fun readInt () =
    valOf (TextIO.scanStream (Int.scan StringCvt.DEC) TextIO.stdIn)

fun int_pow (x, y) =
    let
        fun loop n =
            if n = 0 then 1
            else x * loop (n - 1)
    in
        loop y
    end

val () =
    let
        val n = readInt ()

        val numOfHitsForMoreThanHalf =
            let
                fun loop need current =
                    if need < current then 0
                    else 1 + loop need (current * 2)
            in
                loop n 1 - 1
            end
                
        val rest = n - int_pow (2, numOfHitsForMoreThanHalf)

        val ans = if rest = 0 then numOfHitsForMoreThanHalf
                  else numOfHitsForMoreThanHalf + 1
    in
        print (Int.toString ans)
    end