Petals Around the Rose: Fraternity Register

Took about an hour of thinking about it after my wife showed me, then 15 minutes to write a program to do it and then a few minutes to reduce it to a single line equation.

I think the issue isn't that 'smarter' poeple take longer, but that more 'analytical' people take longer. I spent the most of the first hour spinning thorugh algorithms, but then thought about the name and went looking for flowers! Once I stopped thinking too much, the answer popped right up.