you're probably missing something then, people here are pretty good at spotting the best solutions

Having the same issue, I don't understand the instruction. It says return '' if more than one possible pair of a,b values, yet the tests ask us to return two pairs of a,b values?

Edit:
Honestly, just ignore that criteria and anything about the amount of a,b pairs, just make a solution which returns the a,b pairs quickly and you'll pass.