
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
Suppose that each of  $n$  people knows exactly  one piece of information and all  $n$  pieces are  different.  Every time person  $A$  phones person  $B$ ,  $A$  tells  $B$  everything he knows, while tells  $A$  nothing. What is the minimum of phone calls between pairs of people needed for everyone to know everything?

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