import java.util.Scanner;


public class no47 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int bis = 1;
		int cnt = 0;
		while(true){
			if(bis==N){
				break;
			}else if(bis<=N){
				bis *= 2;
				cnt++;
			}else{
				break;
			}
		}
		System.out.println(cnt);
	}

}