
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 the Cartesian coordinate system, given the point $M(m-1,2m+3)$.  
$(1)$ If point $M$ lies on the $y$-axis, find the value of $m$.  
$(2)$ If point $N(-3,2)$, and the line $MN$ is parallel to the $y$-axis, find the length of the line segment $MN$.

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