import java.util.Scanner;

public class FizzBuzz {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double a = sc.nextDouble();
		int result = 0;
		if (a > 1) {
			for (int i = 1; i <= 100000000; i++) {
				a = Math.ceil(a / 2);
				result++;
				if (a <= 1) {
					break;
				}
			}
		}
		System.out.println(result);
	}

}