package main import ( "bufio" "fmt" "math" "os" "strconv" ) var sc = bufio.NewScanner(os.Stdin) func nextInt() int { sc.Scan() i, e := strconv.Atoi(sc.Text()) if e != nil { panic(e) } return i } func main() { n := nextInt() for i := 0; i < n; i++ { if float64(n) < math.Pow(2, float64(i)) { fmt.Println(i) break } } }