Proof Writing & Problem Solving · Easy problem

A staircase is climbed taking $1$ or $2$ steps at a time. If $W(n)$ counts the ways to climb $n$ steps, then $W(1) = 1$, $W(2) = 2$, and for $n \ge 3$, $W(n) = W(n-1) + W(n-2)$ (the first move is a $1$ or a $2$). This is the setup for a strong induction. What is $W(9)$?