
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 company purchases 400 tons of a certain type of goods every year, buying $x$ tons each time. The freight cost is 40,000 yuan per time, and the total annual storage cost is $4x$ thousand yuan. Determine the optimal value of $x$ to minimize the sum of the total freight and storage costs for the year.

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