I really enjoyed solving that. It didn't take very long at all (but was very satisfying!). It reminds me of an old story (of which I can't verify) about Gauss

I really enjoyed solving that. It didn't take very long at all (but was very satisfying!). It reminds me of an old story (of which I can't verify) about Gauss while in school solving a summation using a very neat observation. Enough said!