
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
From point \( A \) to point \( B \) at 13:00, a bus and a cyclist departed simultaneously. After arriving at point \( B \), the bus immediately traveled back and met the cyclist at point \( C \) at 13:10. After returning to point \( A \), the bus headed to point \( B \) again without delay and caught up with the cyclist at point \( D \), which is located \(\frac{2}{3} \) km from point \( C \). Find the speed of the bus (in km/h) if the distance between points \( A \) and \( B \) is 4 km, and the speeds of the bus and the cyclist are constant.

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