This is wrong, though, as cases like `oneight` should return `83` whereas I replace the `one`s first, so that `1ight` will remain that way. See <https://www.reddit.com/r/adventofcode/comments/1884fpl/2023_day_1for_those_who_stuck_on_part_2/>.
This is my very first piece of Rust code. When it compiled for the first time, the result was what it should be, so I am happy :-). It did take me > 1 hour to solve this...
