Bhadra’s house has a staircase with 12 steps. She can go down the steps one at a time or two at a time. For example, she could go down 1 step, then 1 step, then 2 steps, then 2, 2, 1, 1, 1, 1. In how many different ways can Bhadra go down the 12 steps, taking one or two steps at a time? How can you ensure that you have found all possible ways?