Different sculk sensor signal from bookshelf slot filled/taken from

Shulk sensors should be able to give off different Redstone signals based on which slot is interacted with. For example, when a skulk sensor "hears" a book taken from the third slot, it should emit a Redstone signal of 3. This way, players could create puzzles similar to puzzles in movies in which a character pulls a book from a bookshelf to unlock a secret door.

Thank you for reading :)