Solve the following math problem step by step. The last line of your response should be of the form Answer: \boxed{$Answer} where $Answer is the answer to the problem.

<image>The diameters of $\odot A, \odot B,$ and $\odot C$ are 10, 30 and 10 units, respectively. Find BY if $\overline{A Z} \cong \overline{C W}$ and $C W=2$.