### Collatz

The Collatz conjecture proposes that the below process will reach 1 regardless of the starting number:

- If the current number is even, divide it by 2.
- Otherwise, multiply the current number by 3 and add 1.

For example, starting with 5, it takes five steps to reach 1:

- 5 is odd, so multiply it by 3 and add 1 to get 16.
- 16 is even, so divide it by 2 to get 8.
- 8 is even, so divide it by 2 to get 4.
- 4 is even, so divide it by 2 to get 2.
- 2 is even, so divide it by 2 to get 1.

Write a function `collatz`

that takes an `int`

parameter and returns how many steps of the Collatz process
are required to get from it to 1. Assume that the parameter is always positive.