
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
The function \( g \), defined on the set of ordered pairs of positive integers, satisfies the following properties:
\[
\begin{align*}
g(x, x) &= x, \\
g(x, y) &= g(y, x), \quad \text{and} \\
(x + 2y)g(x, y) &= yg(x, x + 2y).
\end{align*}
\]
Calculate \( g(18, 66) \).

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