ghyamugyen [ʝa.muˈɟɛn], meaning “an easy problem, a piece of cake”. This is literally “one-four” (ghyam “one” + ugyen “four”), with the implication that the problem is as easy as adding one and four. With Kharulian mathematicians making important discoveries in number theory, mathematical idioms popped up now and then amongst the literate.
The choice of one and four as the numbers may be because five is a nice round number… or because it just sounds better than other combinations of simple numbers.