I was struggle when i first saw it but i solve in the very first attempt after returning.
Nice puzzle. A good spread of lessons here and a puzzle in itself at the end wraps it all together, That was a hard elementary 😅 This one was very well thought! Caught out trying to do too much at once. Very succinct. I had some troubles with finding the last 4 steps (for 324). And even after solving I'd still expect my 328 to be the shortest, lol.