
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 $\triangle ABC$, the sides opposite to angles $A$, $B$, and $C$ are $a$, $b$, and $c$, respectively. Given vectors $\overrightarrow{m}=(a, \frac{1}{2})$ and $\overrightarrow{n}=(\cos C, c-2b)$ such that $\overrightarrow{m} \perp \overrightarrow{n}$.
(I) Find the measure of angle $A$;
(II) If $a=1$, find the range of the perimeter $l$ of $\triangle ABC$.

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