What a truly excellent idea.
I'll think about a good answer. Luckily, I don't really want to win first prize here. If I did, I'd reply "nil" and send you a nasty virus that obliterates your whole hard drive. My "nil" would be a certified correct answer.
But since you are such a nice person (and I don''t have such virus), I won't do that !
I hope nobody gets wrong ideas here...
I can't be the first to congratulate you with this birthday, can I ???
C O N G R A T U L A T I O N S ! ! ! ! ! ! ! ! !