The title doesn’t give a hint of what the problem is or why it’s annoying, but it’s an interesting problem: how efficiently can you determine whether two finite

The title doesn’t give a hint of what the problem is or why it’s annoying, but it’s an interesting problem: how efficiently can you determine whether two finite groups are isomorphic. It’s annoying because it seems it should be easier than it is, given that you have so much structure to work with.