D. Collatz conjecture

考拉兹猜想（也被稱為 猜想）指出：給定一個開始的正整數 ，我們反覆進行以下操作之後最終會得到 ：

我們定義 為 變成 需要的操作數。

例如，如果我們從 開始，序列應該是：。因此，。

你需要寫一個程式，在給定正整數 時找出 的值。

The Collatz conjecture, also called the conjecture, states that: Given a starting positive integer , we can eventually obtain after carrying out the following operation repeatedly:

We define as the number of operations needed before becomes .

For example, if we start from , the sequence would be: . Therefore, .

You are asked to write a program to find given a positive integer .

輸入只有一個正整數，。

The input consists of only one integer .

輸出一個正整數， 的值。

Output exactly one positive integer, the sum .

Sample input

3

Sample output

8

對於全部測試數據，滿足 。

For all test data, .