import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int ansNum = sc.nextInt();
        int currentNum = 1;
        int powCount = 0;
        while (ansNum > currentNum) {
            currentNum *= 2;
            powCount++;
        }

        System.out.println(powCount);
    }
}