Re-read the original conundrum statement, because, honestly, you probably missed something. Take a few minutes to really understand the question.
Proceed to Step 2: Break Down the Problem
Try Method 2 for an Alternative ApproachTake a walk, clear your head, and come back to the problem with fresh eyes. You know, the usual.
Or, if you're really stuck, just pretend you're a conundrum-solving superhero. Fly around the world, find a wise old sage, and have them reveal the answer in a flash of inspiration. Works for me every time.