Help choosing best way to prove logic problem

Ok I don't need answers just a little shove in the right direction. It's not an incredibly hard logic problem, I just want to know the best route to take to prove it. Here's the question,

If 'R' and 'S' are irrational then R^S is irrational.

I was thinking contra-positive would be best. So assume not P and prove not Q. So this means I would have 'R' and 'S' are rational and prove that R^S is rational. I know that if a number is rational then it can be represented by two integers (m/n) but I'm just not sure how to work that in to get my proof solid. Thanks in advanced.