We have two blocks. Lets call them A and B. Two medium blue squares are in block A. Below a medium black square there is medium blue square number two. Below the medium black square and medium blue square number two is medium blue square number one. Block B is above block A. It contains one medium yellow square. One medium blue square is also in this block. The medium blue square is below the medium yellow square.
What is below the yellow thing? a medium blue square that is in block B or a medium blue square number two?
medium blue square  that is in block B medium blue square  number two both of them none of them