"Y" is a vowel over here, but Americans - go figure.
Vowels are "AEIOU, and sometimes Y"

And I probably could've done this in fewer than 5 if I'd stopped to think. "Yeah, that letter is first, and this other letter can't go second, fourth or fifth, so it HAS to go third, and this other letter can't be last or second, and..."
When I started this, I often screwed up because I entered something too quickly, without his critical thinking step.