[up to this 3D shape]
- Start from
- Close the lid by turning 180 degrees the two adjacent horizontal tiles on the right
- The two stacked tiles prodruding from the resulting cube can be opened by changing their hinging
side
- Insist in opening these two tiles untill they become coplanar, resulting in a 1x2x2 3D structure with
a pair of internal adjacent tiles, one of which becomes a flap
- Turn 90 degrees the newly created flap into the final shape
