I don't wanna spoil anything, but I admit that it's hard, so technically there are 3 endings, Good, Neutral and Bad.
Good is the "right combination", it might be annoyingly specific, but I had to be a little biased, it's the way I make my cocoa always lol. Truthfully tho, the Good and Neutral ending are similar, so as the game goes: Enjoy cocoa on your own way ^^ But the Bad ending on the other hand :)