public class Bits {
  public static void main (String[] args) {
    int N = Integer.parseInt(args[0]);
    int times = 0;
    //number of time I need to divide N by 2 until it's less than 1.
    while (N/2 >= 1) {
      times = times + 1;
      N = N/2;
    }
    if (N < 0) System.out.println("illegal input");
    else System.out.println(times);
  }
}