/* package whatever; // don't place package name! */ import java.util.*; import java.lang.*; import java.io.*; /* Name of the class has to be "Main" only if the class is public. */ class Ideone { public static void main (String[] args) throws java.lang.Exception { // your code goes here Scanner sc = new Scanner(System.in); String N = Integer.toBinaryString(sc.nextInt()); System.out.println(("1".equals(N)) ? 0 : N.length()); } }