package main

import (
	"fmt"
)

func resolve(N int) int {
	ret := 0
	for N > 1 {
		N = (N + 1) / 2
		ret += 1
	}
	return ret
}

func main() {
	var N int
	fmt.Scanf("%d\n", &N)
	fmt.Println(resolve(N))
}