mačji kašalj

1. colloq. a piece of cake; peanuts
   Ovaj ispit je za mene mačji kašalj. — This exam is a piece of cake for me.
   Petsto evra nije mačji kašalj. — Five hundred euros is not peanuts.

Often in the negative: nije mačji kašalj, meaning "it's no small thing".