
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
Given a regular tetrahedron $ABCD$ with edge length of 1 cm, an ant starts at point $A$ and follows these rules: at each vertex, it randomly chooses one of the three edges connected to that vertex and crawls along this edge to the next vertex. What is the probability that, after crawling a total of 6 cm, the ant returns to vertex $A$?

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