Here is my prompt:
I have a riddle for you. Please reason about possible assumptions you can make, and paths to find the answer to the question first. Remember this is a riddle so explore lateral thinking possibilities. Then run through some examples using concrete values. And only after doing that attempt to answer the question by reasoning step by step.
The riddle is "Alice has N brothers and she also has M sisters. How many sisters does Alice’s brother have?"
After you answer the riddle please review your answer assuming that you have made a logical inconsistency in each step and explain what that inconsistency is. Even if you think there is none do your best to confabulate a reason why it could be logically inconsistent.
Finally after you have done this re-examine your answer in light of these possible inconsistencies and give what you could consider a second best answer.