The sequence of Collatz

Let $n$ be any strictly positive natural number. Consider the following process. If $n$ is an even number, we divide it by two. Otherwise, we multiply it by 3 and add 1 to it. When we reach 1, we stop. For instance, starting with 3, we obtain the sequence $3,~ 10,~ 5,~ 16,~ 8,~ 4,~ 2,~ 1 .$

Since 1937 it is conjectured that this process ends for any initial $n$ , although nobody has been able to prove it. In this problem, we do not ask you for a proof. You only have to write a program that prints the number of steps that it takes to reach 1 for every given $n$ .

Input

Input consists of several natural numbers $n \ge 1$ .

Output

For every $n$ , print how many steps are needed to reach 1. Suppose that this number is well defined, that is, that the conjecture of the statement is true.

Problem information

Author: Unknown
Translator: Carlos Molina

Generation: 2026-01-25T11:51:02.508Z