
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 \( f(n) \) is a function defined on all positive integers and takes positive integer values. For all positive integers \( m \) and \( n \), it holds that
\[ f(f(m) + f(n)) = m + n. \]

Find all possible values of \( f(1988) \).

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