
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
For any positive integer $n$, let 
$f(n) =\left\{\begin{matrix}\log_{5}{n}, &\text{if }\log_{5}{n}\text{ is rational,}\\ 0, &\text{otherwise.}\end{matrix}\right.$
What is $\sum_{n = 1}^{1997}{f(n)}$?
A) 5
B) 9
C) 10
D) 12

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