import java.util.Scanner;

public class Yuki5 {
	
	public static void main(String[] args) {
	
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		int count = 0;
		int x = 1;
		while(x<n){
			x = x + x;
			count++;
		}
		System.out.println(count);
	}
}