
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 sequence of integers $\left\{a_{n}\right\}$ satisfying $a_{n}=a_{n-1}-a_{n-2}$ for $n \geq 3$, if the sum of the first 1492 terms is 1985 and the sum of the first 1985 terms is 1492, find the sum of the first 2001 terms.

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