Part 187: (Eva's Hint)

"That part sounds like some kind of word game. After all, 'kyu-kyu-' means emergency, and 'kyu-' means nine. If you write two nines together, it looks like 99, doesn't it?"
"So, if you add something to 99, you get an ambulance?"
"Hmm. Why does some number added to 99 get you an ambulance... Ah, I've got it!"
"Huh, really?! Hey, what is it?!"
"I'll give you a hint. You've got a big advantage here that most people around the world don't have. *giggle* Then again, even people from other countries could narrow it down to two answers with a little math."