import java.util.Scanner;

public class Yukicoder {

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

        int N = sc.nextInt();
        int biscuit = 1;
        int count = 0;
        while (N > biscuit) {
            biscuit *= 2;
            count++;
        }

        System.out.println(count);
    }
}