Given the task definition, example input & output, solve the new input case.
In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. There are several possible answers, you'll need to choose the proper one. Carefully read the given text, pay special attention to the marked number, think about what (unwritten) information the marked number holds inside, choose the most adequate word(s) from the optional answers. If none of them seems right to you, there's also an option for other. If your answer is "REFERENCE", also write the reference entity, otherwise write the implicit option name. Options to choose from are:
REFERENCE: Some object which is being mentioned in the text before or after the target number. The reference answer has a higher priority than any other. If both Reference and another answer are possible, prioritize the Reference.
YEAR: Describing a calendric year
AGE: Describing someone's age
CURRENCY: Reference to some monetary value e.g dollar, euro etc.
PEOPLE: Describing a single/plural persons
TIME: Describing a time of the day. Usually you can add the word o'clock after those numbers.
OTHER: Some other option, which isn't listed here.
Example: Jess Mastriani: No, I don't want another crooler, thank you very much.
 FBI Agent Nicole Scott: But it's good for you. It's got... honeyglaze. Please die for this crooler, Jess.
 Jess Mastriani: I've had _ two _ already. Who eats three croolers in a night? 
FBI Agent Nicole Scott: Take a look. [Nicole takes a huge bite] Mmmmm, Mmmmm, Mmmmm!
Output: REFERENCE crooler
In this example, the number two refers to something that appears in this text. In this example, it refers to the word: crooler.

New input case for you: Ludwig Von Drake:  One of the most important chapters in my book is the _ one _ on what to do with the kids during summer vacation . Well whatever you do , get them out of the house , go to the mountains , go to the beach , go anywhere , but go ! Or you 're gon na go nuts ! Had I known that Family X was going to be on the go so much , I would've chosen Family Y ! But I was determined to hang on until my research was completed .
Output:
REFERENCE chapters