package no047;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int num = 1;
		int ans = 0;
		while(num * 2 < n) {
			num *= 2;
			ans++;
		}
		if (num < n) {
			ans++;
		}
		System.out.println(ans);
	}

}