How do I solve this: $a^{x^y}$

Question

How do I solve this: $a^{x^y}$

I first evaluated the $x^y$ and then put the answer as an exponent of $a$.

I don't know if this is the right way to do it.

And also, what if the expression is like this: $a^{x^{y^z}}$ and so on...

Please help me out.

I am a beginner at Stack Exchange Math, so I don't know know how to format it. Kindly bear with it. Thanks in advance.