
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
How many different four-digit numbers, divisible by 4, can be made from the digits 1, 2, 3, and 4,

a) if each digit can be used only once?

b) if each digit can be used multiple times?

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