
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
There are 20 free chairs in a row. From time to time, a person approaches the chairs and sits on one of the free chairs. When this happens, one of the neighbors, if any, immediately stands up and leaves (these two do not sit together). What is the maximum number of chairs that can be occupied?

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