
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 person has 10 friends and invites some of them over during several days, ensuring that the same group never comes over more than once (on some days, he may invite no one). How many days can he do this?

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