hailstone() - An interesting unsolved problem in mathematics concerns what is called the hailstone sequence of integers. This sequence is defined as follows: start with any integer. If that number is odd, then multiply it by 3 and add 1. If it is even, then divide it by 2. Now, repeat. For example, if we start with the number 5, we get the following sequence: 5, 16, 8, 4, 2, 1, 4, 2, 1, 4, 2, 1, . . . Here, the subsequence 4, 2, 1 is reached which produces a loop. It was conjectured (by mathematician Lothar Collatz) that no matter what number you start with, you will always end up stuck in the 4, 2, 1 loop. It has, in fact, been shown to hold for all starting values less than 5 x 2^60 ≈ 5.764 x 10^18. However, it still has not been proven for all numbers. You are given a starting number of a hailstone sequence, and should return the number of values in that sequence up to (and including) the first 1.