import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long n = sc.nextLong();
    long ans = 0;
    while(n > 1) {
      if(n % 2 == 0) {
        n /= 2;
      } else {
        n++;
      }
      ans++;
    }
    System.out.println(ans);
  }
}