Svetlo

While trying to play a game of chess, Pat & Mat realise that all figures are white. So they add color to one set... but mistakenly color all pawns black. Of course, that doesn't trouble them as they just exchange between white and black pieces and end up with 16 each, despite not matching the shapes. The problem here is that light bulb needs replacing and for some reason that is not as easy to do as it sounds.