I found out that trim().split("\n") is a few μs faster than lines() on my machine ... you might be able to get that a few μs faster :)

Beautiful.

Maybe I have the dumb, but running this I get an error:

thread ‘main’ panicked at ‘called ‘Result::unwrap()’ on an ‘Err’ value: ParseIntError { kind: Empty}

Doesn’t seem to like the first unwrap, do you have any idea why?

Edit: it doesn't like split("\n\n"), the inputs are directly off the site with no apparent leading or trailing whitespace, using split_whitespace() no longer errors but obviously the result is incorrect.