import java.util.Scanner;

class no642{
	public static void main(String[] args) {
		Scanner stdIn=new Scanner(System.in);
		int n=stdIn.nextInt();
		int x=1;
		int i=0;
		while(x<n) {
			x=x<<1;
			i++;
		}
		while(x!=n) {
			x--;
			i++;
		}
		System.out.println(i);
	}
}