...which, essentially, means that you do, indeed, need to guess (since Ayu was being so obscure with her answer).
Other players may also be able to help you with the combinations if you ask politely (but make sure answers are not given over Main chat channel, as that is against the rules).
What the others said basically, yes you have to guess. Each item mentioned is used in a combination, and only once. So when you find some of the combinations, the other will be easier afterwards.