Tap the drawer on the left side (there was a sword before but now it's gone). It will be open. Take the block.
Look at the colored books on the bookshelf. Remember the order:
Yellow #1, Black #2, Blue #3, Red #4, Green #5.
Look at the squares to the left of the door.
Insert the colored blocks to the bottom slot, and the other blocks to the top slot.
Using the book colors, figure out the numbers for the top slots: Black #2, Yellow #1, Blue #3, Green #5, Red #4: Solution = 21354
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