Given a set of [FACTS], you have to answer the [QUESTION] by reasoning from the [FACTS].

[FACTS]:
NAME_1 is a wolf
wolves are afraid of sheep
mice are afraid of cats
winona is a human
sheep are afraid of humans
cats are afraid of mice
NAME_2 is a wolf
gertrude is a wolf
NAME_3 is a sheep

[QUESTION]: what is NAME_3 afraid of?
[ANSWER]: 