
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 transportation company purchased a batch of luxury buses for passenger transport. According to market analysis, the total profit $y$ (in ten thousand yuan) of operating each bus is related to the number of operating years $x$ ($x \in \mathbb{N}$) by the equation $y = -x^2 + 12x - 25$. Determine the number of years each bus should be operated before being scrapped to maximize the average annual operating profit.

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