import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int b = 1;
        int cnt = 0;
        while (true) {
            if (b >= n) {
                break;
            }
            b *= 2;
            cnt++;
        }
        System.out.println(cnt);
        scan.close();
    }
}