
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
Determine all possible \( m \times n \) rectangles that can be completely covered by the given shape composed of 6 unit squares (including its rotations and reflections). The conditions are:
1. When covering the rectangle, there should be no gaps and no overlapping shapes.
2. The shape cannot extend outside the rectangle.
(From the 45th IMO)

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