import java.util.Scanner;

public class BiscuitsBeDoubled {

	public static void main(String[] args) {

		int biscuits = 1;

		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();

		for (int i = 0; biscuits <= N; i++) {
			biscuits = biscuits * 2;
			
			if(biscuits <= N){
				System.out.println(i);
			}
		}
		

	}

}