Write a program that guesses the number. It is known that it is positive integer and does not exceed some predetermined number n.

The guesser is allowed to ask only questions of the form

• ? A

meaning the question "The guessed number is greater than A?". To this question, you can get only one of two answers: "Yes" or "No". The number of asked questions should be minimum for any number not exceeding n.

Input

One positive integer n (1 ≤ n ≤ 2 ·109).

Output

Print the minimum possible number of questions for any number not exceeding n.