
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
The "May Day" holiday is approaching, and a certain unit arranges for four people, A, B, C, and D, to be on duty from May 1 to May 4, with one person per day. A can only be on duty on May 1 or May 4, and the duty days of A and B cannot be adjacent. The number of possible arrangements is $\_\_\_\_\_\_$.

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