
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
In a regular $1000$-gon, all the diagonals are drawn. What is the maximum number of diagonals that can be chosen such that among any three selected diagonals, at least two have the same length?

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