
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 pages of a book are numbered from 1 to \(n\). When the page numbers were summed, one of the page numbers was mistakenly added twice, leading to an incorrect sum of 2630. Determine which page number was added twice.

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