
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 December of this year, Xiang'an District will organize a high school basketball league. At that time, a certain number of teams will be selected from each school to participate in the competition. The competition format is a single round-robin (each pair of teams only plays one game). It is planned to arrange 15 games. How many teams should be invited to participate in the competition?

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