The adverb in the sentence is <u><em>very.</em></u>
An adverb is an expression that modifies something.
<em>"a word or phrase that modifies or qualifies an adjective, verb, or other adverb or a word group, expressing a relation of place, time, circumstance, manner, cause, degree, etc. (e.g., gently, quite, then, there )."</em>
