Taking advantage of the tools you already know, draw blue stairs like the ones that are shown in the image.

The head starts in the origin (meaning, in the edge South-West) and must be at the right bottom of the end of the stairs.

Look at the image:

GBB/1.0 size 4 4 cell 0 1 Azul 1 Negro 0 Rojo 0 Verde 0 cell 0 0 Azul 1 Negro 0 Rojo 0 Verde 0 cell 1 1 Azul 1 Negro 0 Rojo 0 Verde 0 cell 2 0 Azul 1 Negro 0 Rojo 0 Verde 0 cell 1 0 Azul 1 Negro 0 Rojo 0 Verde 0 cell 0 2 Azul 1 Negro 0 Rojo 0 Verde 0 head 2 0