
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, resulting in an incorrect sum of 2550. What was the page number that was added twice?

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