import java.util.Scanner;

public class Bisuketto {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		final int N = scan.nextInt();
		int from = 0;
		int to = 0;
		int count = 0;
		for(int i=0;Math.pow(2,i)<N;i++) {
			count ++;
		}
			System.out.println(count);
	}


}