import java.io.*;
import java.util.*;

class Main{
  public static void main(String[] args) throws IOException{
    Scanner scan=new Scanner(System.in);
    int n=Integer.parseInt(scan.next());
    int count=0;
    
    do{
      if(n==1){
        count=0;
      }else{
        count++;
      }
    }while(Math.pow(2,count)<n);
    System.out.println(count);
  }
}