package main

import (
        "bufio"
        "fmt"
        "os"
        "strconv"
)

func nextInt() int {
        i, e := strconv.Atoi(nextString())
        if e != nil {
                panic(e)
        }
        return i
}

func nextFloat() float64 {
        f, e := strconv.ParseFloat(nextString(), 64)
        if e != nil {
                panic(e)
        }
        return f
}

func nextString() string {
        var sc = bufio.NewScanner(os.Stdin)
        sc.Split(bufio.ScanWords)
        sc.Scan()
        return sc.Text()
}

func main() {
        N := nextInt()
        count := 0
        now := 1
        for N > now {
                now *= 2
                count++
        }
        fmt.Println(count)
}