Collatz Steps

**Description:** Starting from n, repeatedly: if n is even, n -> n/2; if odd, n -> 3n + 1. The sequence reaches 1 for every tested input. Count the steps **recursively** to reach 1 (a starting n of 1 is 0 steps). **Input:** One line: n (1 <= n <= 10^6). **Output:** One integer — the number of steps to reach 1. **Example:** 6 -> 8 (6 3 10 5 16 8 4 2 1).