package main

import (
	"fmt"
)

func main() {
	var N, foo, i int64
	fmt.Scan(&N)
	if N==1{
		fmt.Println(0)
		return 
	}
	foo = 1
	for i=0; i<N; i++{
		foo *= 2
		if foo>=N{
			fmt.Println(i+1)
			break
		}
	}
}