Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

Input: Consider Input: the cyclostomes (or cyclostomata) are the lamprey and hagfish.

Output: cyclostome

Input: Consider Input: lactarius torminosus, commonly known as the woolly milkcap or the bearded milkcap, is a mushroom in the genus "lactarius".

Output: lactarius torminosus

Input: Consider Input: aluminium iodide is any chemical compound made up of only aluminium and iodine.
Output: aluminium iodide