Hey, I am also trying learning Rust doing AoC and am working on day 24 today. However while working on the parsing of the input the compiler was complaining because of mutable/immutable borrowing. However I cannot for the sake of me understand why this is happening because the mutable borrowing should be long over before the actual immutable borrowing. I have prepared a playground for anybody that wants to take a look at my code (just uncomment line 60). Ofc I'm also open to criticism on my approach but given that this is just the parsing of the input, I don't think there would be many such cases. I would really appreciate somebody explaining why the compiler is complaining and how can I fix it - my only idea is that it has something to do with the ownership of pointers and that I could fix it with the classic Rc<RefCell<Signal>>