
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
The difference of an arithmetic sequence is 3. What is the first term if the sum of the squares of the first 1001 terms is equal to the sum of the squares of the next 1000 terms?

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