
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 smaller square with side length 4 units is positioned within a larger square with side length 9 units. The smaller square is placed such that its one vertex is at the center of the larger square. Calculate the area of the black region that is not covered by the smaller square.

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