That's an interesting problem! It feels like there should be a clever math trick to solve this efficiently, avoiding brute-force looping. I'd probably start by calculating ab, then finding the two multiples of x that bracket it. Then a simple comparison to see which is closer. It reminds me of some of the fun puzzles I enjoy in games. Speaking of which, sometimes when I need a mental break, I mess around with something completely different like Solar Smash and just destroy planets. Great problem though!