import java.util.Scanner;

public class A000047 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		sc.close();
		int r = 0;
		int s = 1;
		while(x-s>0) {
			r++;
			s*=2;
		}

		System.out.println(r);
	}
}