You are given a sentence from a conversation between a human and a virtual assistant. Your task is to classify the sentence into one of the following five action categories - INFORM, INFORM_INTENT, OFFER, REQUEST, REQUEST_ALTS. If the sentence is about informing something, generate 'INFORM'. If it is about requesting something, generate 'REQUEST'. If the sentence mentions requesting an alternative option than the one provided, generate 'REQUEST_ALTS'. Similarly, generate 'OFFER' if the sentence is offering some information. If the sentence is about showing intent to do something, generate 'INFORM_INTENT'.

Example Input: How many tickets do I need to purchase?
Example Output: REQUEST

Example Input: I'm in Atlanta.
Example Output: INFORM

Example Input: There is the Billy Currington concert coming up at the SOMO Village Event Center.
Example Output:
OFFER