Μy answer is 6
My reasoning is based on the following subtractions and additions.
Some observations that might eventually amount to something, or not:
Without the artist's signature, it's hard to know if the painting is oriented as intended. It could be upside-down. It could be sideways too, but I for one find it more aesthetically pleasing in portrait position.
When we do get it right side up, there's no guarantee that the information ...