
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
Given the following algorithm:  
Step 1, input the value of $x$.  
Step 2, if $x > 4$, calculate $y = x + 2$; otherwise, proceed to the next step.  
Step 3, calculate $y = \sqrt{4-x}$.  
Step 4, output $y$.  
When the input $x = 0$, the output $y = \_\_\_\_\_\_$.

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