Downvoted because I don't think this should be at the top of the discussion. I always read comments first, especially with a title like "Hello, World" that doesn't give any clue about the content; and now I don't get a chance to think about this puzzle because the spoiler was the first thing I saw.

EDIT: To be clear, I am not downvoting because I think that this comment is unconstructive; clearly it is a useful contribution. At least as good as, and probably better than, having it appear later would be having more whitespace between the spoiler warning and the actual spoiler.