Bebras 2021 - Level 4 Question 4

The colour festival is approaching. Residents of the colourful city decide to repaint their homes in one of three colours: blue (B), red (R) and green (G). They agree that a house must not have the same colour as a neighbouring house or the house directly opposite across the street. The picture shows some houses already painted.



Which colours can the beaver’s house be painted to satisfy these conditions?