
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
A stack of books has 15 books on the bottom shelf, and each successive shelf has two fewer books than the one below it, ending with one book on the top. How many books are in the stack?

Present the answer in LaTex format: \boxed{Your answer}
user